An oil-drilling barge sank in the Gulf of Suez, leaving at least four crew members dead and four others missing.

According to the Egyptian government, 22 people were injured when the Adam Marine 12 capsized on Tuesday night in the Gebel el-Zeit area.

Egyptian media reported that the vessel was being towed to a new site at the time of the incident, according to Al Jazeera.

Four of the injured were flown to the hospital by air, while 18 others were taken by ambulance, according to Egypt’s Ministry of Health.

The Ministry of Petroleum and Mineral Resources shared photos on Wednesday showing Minister Karim Badawi visiting survivors at El Gouna Hospital in Hurghada, accompanied by Labour Minister Mohammed Jibran and Red Sea Governor Amr Hanafi.

Hanafi stated that Egyptian navy ships joined the search-and-rescue operation for the missing crew members.

Gebel el-Zeit, located about 300 km (186 miles) south of the Suez Canal, is a key oil production area in Egypt.