Ormoc city, Philippines (BBN)-At least 36 people have died after a passenger ferry capsized off the coast of Leyte in the central Philippines.

The Kim Nirvana was carrying 173 people when it overturned in rough waters just outside the port of Ormoc, reports BBC.

Philippine coast guard officials told the BBC the rescue operation was ongoing but gave no further details.

The chair of the Philippine Red Cross, Richard Gordon, said that between 50 and 70 people had been rescued from the boat, which was visible from the shore.

“Between 50 and 70 people have been rescued and have been provided with food, water and blankets,” he told the BBC.

“We’re sending an ambulance and divers to the area to help with the search and rescue.”

Ciriaco Tolibao, an official at Ormoc’s disaster risk reduction and management office, told the AFP news agency that divers were searching inside the upturned ship.

Local reports said the ferry was heading for the central islands of Camotes, in Cebu province, to the south-west of Leyte. The cause of the sinking is not yet known.

People in the Philippines rely on ferry services to get around its thousands of islands, but vessels are often poorly maintained, leading to scores of deaths at sea every year.