Fifteen of the Greek rescue team were injured, including seven in a critical condition, Othman Abduljaleel told a televised news conference. Two of the Libyan family were also critical, he said.

The Greek Armed Forces said a bus carrying medical personnel collided with a vehicle moving in the opposite direction, but it did not confirm the deaths.

“The causes and circumstances of the incident are being investigated in cooperation with the Libyan authorities, while an operation is underway to gather the personnel in Benghazi and repatriate them,” it said in a statement.

The Greek foreign ministry was not immediately available to comment on Abduljaleel’s statement regarding the killing of four Greeks. According to a diplomatic source, the Greek rescue team had 16 members plus three interpreters.

Thousands of people were killed after two dams above Libya’s eastern city of Derna broke on Sept 10 during a powerful storm, bringing down residential blocks lining a usually dry riverbed as people slept. Many bodies have been washed out to sea.