Children in the English town of Wooler in Northumberland are temporarily without a playground after workers found 176 unexploded World War II bombs buried underneath the play area.

The first ordnance was discovered Jan. 14, when workers began expanding the play area and encountered what looked like a bomb while excavating the site.

Northumberland County Councillor Mark Mather told Sky News they put a roughly 50-yard cordon around the site after the first bomb was unearthed and alerted the army.

“The army bomb disposal team came out to the first one on the first day, and then the second bomb, the next day,” Mather said.

But as more of what he described as “training devices” continued to crop up, the parish council had to hire an outside firm to fully examine the playground. Brimstone Site Investigations, a bomb disposal company, found more than 150 bombs over the next two days.

The Wooler Parish Council described the ordnance as “practice bombs” in a news release but clarified that despite the term they still pose a threat to children, as they’ve been found with their fuses intact, along with a “detonator burster and smoke filling.”

The council told the BBC that Wooler formerly hosted a Home Guard training center. After the war, apparently, they disposed of their ordnance by burying it in several pits ― pits that later became part of Scotts Park.

“It’s quite something to think the children have been playing on bombs and it’s been a really challenging situation,” Mather told the BBC.

“We’ve only cleared about a third of all the park, and we could still find another pit with more bombs in.”