Five people died when a ferry capsized in the Philippines on Thursday, the authorities said, renewing concerns about maritime safety in the archipelagic nation.

The Philippine Coast Guard said 252 of the 257 people who were aboard the vessel, the Mercraft 3, had been rescued. The ferry had been traveling on rough seas from Ungos port in Real, a town east of Manila, to Polillo Island when it capsized around 11:30 a.m. on Thursday.

Coast guard vessels and small outrigger fishing boats were involved in the search and rescue operations. “The waves are still very big,” said Froilan Roy Firme Rojano, an officer at the Polillo municipal police station. “These are very difficult conditions.”

Ferry accidents are common in the Philippines, particularly during the typhoon season. In 2008, at least 800 people were killed when the Princess of the Stars capsized during a storm. A 1987 collision between the Doña Paz ferry and an oil tanker is believed to have killed more than 4,300 people.