Militants loyal to the terror group Islamic State captured 20 foreign doctors and nurses on Monday who were waiting for a bus to take them to Libya’s capital,Tripoli, according to an official.

The medical staff worked at the Ibn Sina hospital in Sirte and were taken hostage by the Tafkiri group, which is affiliated with ISIS.

An official of a militia battling the Tafkiri group had reported the kidnappings on Monday, The Associated Press reports.

The foreigners were part of an exodus of people trying to flee Sirte before violence there intensifies.

The official said his battalion helped evacuate the remaining foreign medical crew to Misrata, where his battalion is based.

The militants captured the doctors and nurses so they could take care of their own wounded, according to reports. The nationalities of the hostages were not immediately clear.