Four missing after dive boat sinks at Philippine reef

Rescuers were searching for four people Sunday after a boat carrying more than a dozen scuba divers sank at a World Heritage-listed marine sanctuary in the Philippines, authorities said.

The Philippine Coast Guard said 28 people were rescued after "Dream Keeper" went down on Sunday morning in the pristine waters at Tubbataha Reef off the western province of Palawan.

Four Chinese nationals were among those on board the dive boat.

The owner of the vessel, a dive master and two guests were still missing, coast guard spokesman Rear Admiral Armando Balilo said.

A coast guard vessel and about 10 dive boats were searching the waters.

"It's full of diving enthusiasts now and it's on their bucket list. It's a dream dive," said Balilo, referring to Tubbataha.

The 97,000-hectare (240,000-acre) Tubbataha Reef is one of the country's largest marine protected areas and was listed as a World Heritage Site by the United Nations in 1993.

Despite its protected status, the marine sanctuary is under constant threat from illegal fishing and poaching, according to authorities.