A U.S.-flagged oil tanker has collided with a Portuguese container ship in the North Sea, north of England, with both ships catching on fire, according to officials.

“HM Coastguard is currently co-ordinating the emergency response to reports of a collision between a tanker and cargo vessel off the coast of East Yorkshire resulting in fires aboard both vessels,” the U.K. coast guard said in a statement.

The U.S. ship was identified as the Stena Immaculate, while the Portuguese-flagged container ship was identified as the Solong.

A coast guard helicopter has been sent, as well as a fixed-wing aircraft, several lifeboats and vessels with firefighting capabilities, the coast guard said.

“The incident remains ongoing and an assessment of the likely counter pollution response required is being enacted,” the coast guard said in a statement.

This is a developing story. Please check back for updates.