A ferry carrying about 350 people sank in the southern Philippines Monday morning, leaving at least 18 dead and 28 still missing, according to the coast guard.

The passenger vessel capsized at around 1:50 a.m. local time (1750 UTC) on Monday when the passenger vessel, , departed from ‌Zamboanga for Jolo in Sulu province.

The ferry, MV Trisha Kerstin ⁠3, sank during good weather about a nautical mile (nearly 2 kilometers) from the island village of Baluk-baluk in Basilan province, Romel Dua, a coast guard commander told news agency The Associated Press (AP).

According to the Philippines Coast Guard, the ferry was within its authorized limit of 352 people aboard, including 27 crew members.

"There was a coast guard safety officer on board and he was the first to call and alert us to deploy rescue vessels," Dua said, adding that the safety officer survived.

Rescue operations and investigation underway

So far, the rescue team has managed to save at least 316 people and are still searching for the 28 still missing, Romel Dua, a coast guard commander, told news agency Agence France Press (AFP). 

"A coast guard aircraft is also on the way to help the operation. The Navy and Air Force also sent their assets," Dua, who is based in southern Mindanao, told AFP.

Emergency responder Ronalyn Perez told AFP that the rescuers were struggling to handle the surge of survivors.

"The challenge really is the number of patients that are coming in. We are short-staffed at the moment," Perez said, adding at least 18 had been brought to one local hospital.

Meanwhile, Dua said an investigation was underway to determine the cause of the accident.

 "We cannot say for now the reason of the sinking, but we were instructed to conduct a marine casualty investigation to determine the cause," Dua said.

"As of now, we are focused on the rescue."

Edited by: Saim Dušan Inayatullah