At least 15 people were killed and more than 300 others rescued after an inter-island ferry carrying over 350 passengers and crew sank shortly after midnight off an island in the southern Philippines, authorities said on Monday.

Vessel goes down near Basilan

The passenger and cargo ferry M/V Trisha Kerstin 3 sank about a nautical mile off Basilan while travelling from Zamboanga City to Jolo, according to officials and reports by the Associated Press.

The Philippine Coast Guard said the ferry was carrying 332 passengers and 27 crew members when it encountered what appeared to be technical problems and sank despite good weather conditions.

Massive rescue operation launched

Coast Guard commander Romel Dua said a coast guard safety officer on board managed to alert authorities moments before the ferry went down, triggering an immediate rescue response. The officer survived.

Rescue teams, including coast guard and navy vessels, local fishing boats, a surveillance aircraft and an air force Black Hawk helicopter, were deployed to the area. As of Monday, at least 316 people had been rescued, while search operations continued for possible missing passengers.

Survivors and bodies brought ashore

Basilan Governor Mujiv Hataman said survivors and recovered bodies were taken to Isabela City, the provincial capital. Authorities later confirmed that at least 15 bodies had been recovered. Many survivors were initially brought to the nearby village of Baluk-baluk, close to the site of the sinking.

Emergency responders said local medical facilities were under strain due to the sudden influx of patients.

Cause under investigation

Officials said there was no immediate indication of overloading and that the ferry had been cleared before departure. An investigation has been ordered to determine the exact cause of the sinking.

Maritime accidents remain common in the Philippines, an archipelago of over 7,600 islands, often due to ageing vessels and uneven enforcement of safety norms.