At least 15 people have died after a ferry carrying more than 350 passengers and crew members sank in the waters off the Philippines' southern coast.

Search crews have rescued 316 people on board the MV Trisha Kerstin 3, but at least 28 people are still missing.

The ship, which was both a cargo and passenger ferry, was on its way from the country's southern mainland, Mindanao, to Jolo island further south-west when it issued a distress call at 1:50 local time Monday (17:50 GMT Sunday).

Authorities say they are investigating the cause of the sinking. The Philippines - an archipelago nation of 7,100 islands - has a long history of maritime disasters involving inter-island ferries.

"Based on the account of some survivors, the waters in the area were rough at the time," Philippine Coast Guard spokeswoman Noemie Cayabyab said in a televised interview, according to an AFP report.

A Facebook video by Basilan Governor Mujiv Hataman showed survivors wrapped in blankets as they disembarked from a rescue boat.

Rescuers have been overwhelmed by the influx of survivors, Basilan emergency responder Ronalyn Perez told AFP.

"The challenge really is the number of patients that are coming in. We are short-staffed at the moment," Perez said.

Poor maintenance and overloading have been blamed for past ferry accidents in the Philippines. Despite this, many Filipinos still travel by ferry due to its low costs.

In May 2023, 28 people died after a passenger ferry caught fire. The fatalities included three children, among them a six-month-old baby.

The year before that, at least seven people died after a fire in a high-speed ferry carrying 134 people.