Aviation experts said Thursday that Russian air defense fire was likely responsible for the Azerbaijani plane crash the day before that killed 38 people and left all 29 survivors injured.

Azerbaijan Airlines’ Embraer 190 was en route from Azerbaijan’s capital of Baku to the Russian city of Grozny in the North Caucasus on Wednesday when it was diverted for reasons still unclear and crashed while making an attempt to land in Aktau in Kazakhstan after flying east across the Caspian Sea.

The plane went down about 3 kilometers (2 miles) from Aktau. Cellphone footage circulating online appeared to show the aircraft making a steep descent before crashing into the ground and exploding in a fireball.

Other footage showed a part of its fuselage ripped away from the wings and the rest of the aircraft lying upside down on the grass.

Azerbaijan mourned the crash victims with national flags at half-staff across on Thursday. Traffic stopped at noon, and sirens sounded from ships and trains as it observed a nationwide moment of silence.

Speaking at a news conference Wednesday, Azerbaijani President Ilham Aliyev said that it was too soon to speculate on the reasons behind the crash, but said that the weather had forced the plane to change from its planned course.

“The information provided to me is that the plane changed its course between Baku and Grozny due to worsening weather conditions and headed to Aktau airport, where it crashed upon landing,” he said.

Russia’s civil aviation authority, Rosaviatsia, said that preliminary information indicated the pilots diverted to Aktau after a bird strike led to an emergency on board.

Authorities in Azerbaijan, Kazakhstan and Russia were tight-lipped about a possible cause of the crash but a lawmaker in Azerbaijan blamed Moscow. Rasim Musabekov told the Azerbaijani news agency Turan that the plane was fired on while in the skies over Grozny and urged Russia to offer an official apology.

“Those who did this must face criminal charges,” Musabekov was quoted by Turan as saying, adding that compensations to the victims should also be paid. “If it doesn’t happen, relations will be affected.”

As the official crash investigation started, some experts pointed out that holes seen in the plane’s tail section could indicate that it could have come under fire from Russian air defense systems fending off a Ukrainian drone attack.

Ukrainian drones had previously attacked Grozny, the capital of the Russian republic of Chechnya, and other regions in the country’s North Caucasus. An official in Chechnya said another drone attack on the region was fended off on Wednesday, although federal authorities didn’t report it.

Mark Zee of OPSGroup, which monitors the world’s airspace and airports for risks, said that the analysis of the images of fragments of the crashed plane indicate that it was almost certainly hit by a surface-to-air missile, or SAM.

“Much more to investigate, but at high level we’d put the probability of it being a SAM attack on the aircraft at being well into the 90-99% bracket,” he said.

Osprey Flight Solutions, an aviation security firm based in the United Kingdom, warned its clients that the “Azerbaijan Airlines flight was likely shot down by a Russian military air-defense system.” Osprey provides analysis for carriers still flying into Russia after Western airlines halted their flights during the war.

Osprey CEO Andrew Nicholson said that the company had issued more than 200 alerts regarding drone attacks and air defense systems in Russia during the war.

“This incident is a stark reminder of why we do what we do,” Nicholson posted online. “It is painful to know that despite our efforts, lives were lost in a way that could have been avoided.”

Yan Matveyev, an independent Russian military expert, noted that images of the crashed plane’s tail reveal the damage compatible with shrapnel from a small surface-to-air missiles, such as the Pantsyr-S1 air defense system.

“It looks like the tail section of the plane was damaged by some missile fragments,” he said.

Matveyev added that it remains unclear why the pilots decided to fly hundreds of miles east across the Caspian Sea instead of trying to land at a closer airport in Russia after the plane was hit.

“Perhaps some of the plane’s systems kept working for some time and the crew believed that they could make it and land normally,” Matveyev said, adding that the crew could also have faced restrictions on landing at another venue in Russia.

Caliber, an Azerbaijani news website with good government connections, also claimed that the airliner was fired upon by a Russian Pantsyr-S air defense system as it was approaching Grozny. It questioned why Russian authorities failed to close the airport despite the apparent drone raid in the area. Khamzat Kadyrov, head of Chechnya’s Security Council, said that air defenses downed drones attacking the region on Wednesday.

Caliber also wondered why Russian authorities didn’t allow the plane to make an emergency landing in Grozny or other Russian airports nearby after it was hit.

Asked about the claims that the plane had been fired upon by air defense assets, Kremlin spokesman Dmitry Peskov told reporters that “it would be wrong to make hypotheses before investigators make their verdict.”

Kazakhstan’s parliamentary speaker, Maulen Ashimbayev, also warned against rushing to conclusions based on pictures of the plane’s fragments, describing the allegations of air defense fire as unfounded and unethical.

According to Kazakh officials, those aboard the plane included 42 Azerbaijani citizens, 16 Russian nationals, six Kazakhs and three Kyrgyzstan nationals. Russia’s Emergencies Ministry on Thursday flew nine Russian survivors to Moscow for treatment.

Associated Press writers Jon Gambrell in Dubai, United Arab Emirates, and Aida Sultanova in London contributed to this report.

An Azerbaijani airliner with 67 people onboard crashed Wednesday near the Kazakhstani city of Aktau, leaving at least 32 survivors, according to officials. More than 30 people may be dead.

The plane was en route from the Azerbaijani capital of Baku to the Russian city of Grozny in the North Caucasus.

Kazakhstan’s Emergency Ministry said in a Telegram statement that those on board included five crew. A total of 29 survivors, including two children, have been hospitalized, the ministry told Russia’s state news agency, RIA Novosti.

Another Russian news agency, Interfax quoted medical workers as saying that four bodies have been recovered and emergency workers at the scene as saying that both pilots, according to a preliminary assessment, died in the crash.

The Embraer 190 aircraft made an emergency landing 3 km from the city, Azerbaijan Airlines said earlier.

Kazakhstan’s Emergency Ministry initially said 25 people survived the crash, later revising that number to 27, 28, and then 29 as the search and rescue operation continued at the site of the crash, bringing the supposed death toll down.

The Prosecutor General’s Office in Azerbaijan later reported that at least 32 people survived the crash, adding that the number wasn’t final. Azerbaijan’s Foreign Ministry said in a statement that some of them were in critical condition.

The number of survivors could mean that over 30 people may be dead.

According to Kazakhstani officials, those aboard the plane included 42 Azerbaijani citizens, 16 Russian nationals, six Kazakhstani and three Kyrgyzstani citizens, it said.

RIA Novosti quoted Russia’s civil aviation authority, Rosaviatsia, as saying that preliminary information showed that the pilot had chosen to divert to Kazakhstan’s Aktau after a bird strike on the aircraft led to “an emergency situation on board”.

Mobile phone footage circulating online appeared to show the aircraft making a steep descent before smashing into the ground in a fireball. Other footage showed part of its fuselage ripped away from the wings and the rest of the aircraft, lying upside in the grass. The footage corresponded to the plane’s colors and its registration number.

Some of the videos posted on social media showed survivors dragging fellow passengers away from the wreckage of the plane.

Flight-tracking data from FlightRadar24.com showed the aircraft making what appeared to be a figure-right once nearing the airport in Aktau, its altitude moving up and down substantially over the last minutes of the flight before impacting the ground.

FlightRadar24 separately said in an online post that the aircraft had faced “strong GPS jamming” which “ made the aircraft transmit bad ADS-B data”, referring to the information that allows flight-tracking websites to follow planes in flight. Russia has been blamed in the past for jamming GPS transmissions in the wider region.

In a statement, Azerbaijan Airlines said it would keep members of the public updated and changed its social media banners to solid black.

Azerbaijan’s state news agency, Azertac, said that an official delegation consisting of Azerbaijan’s emergency situations minister, the country’s deputy general prosecutor, and the vice president of Azerbaijan Airlines had been dispatched to Aktau to conduct an “on-site investigation”.

Azerbaijani President Ilham Aliyev, who had been traveling to Russia, returned to Azerbaijan on hearing news of the crash, the president’s press service said. Aliyev was due to attend an informal meeting of leaders of the Commonwealth of Independent States, a bloc of former Soviet countries founded after the collapse of the Soviet Union, in St. Petersburg.

Aliyev expressed his condolences to the families of the victims in a statement on social media. “It is with deep sadness that I express my condolences to the families of the victims and wish a speedy recovery to those injured,” he wrote.

He also signed a decree declaring Dec. 26 a day of mourning in Azerbaijan.

Russian President Vladimir Putin spoke to Aliyev on the phone and expressed his condolences, Kremlin spokesman Dmitry Peskov told reporters.

Speaking at the CIS meeting in St. Petersburg, Putin also said that Russia’s Emergency Ministry sent a plane with equipment and medical workers to Kazakhstan to assist with the aftermath of the crash.

Kazakhstani, Azerbaijani and Russian authorities said they were investigating the crash. Embraer told The Associated Press in a statement that the company is “ready to assist all relevant authorities.”

Associated Press writers Jon Gambrell in Dubai, United Arab Emirates, and Aida Sultanova in London contributed to this report.