MANILA - Eighteen Vietnamese crew members of a cargo ship have been detained after it ploughed into a coral reef in the central Philippines, the coastguard said Tuesday.

The Unicorn Logger, a Panama-flagged freighter, ran aground at a protected marine sanctuary off the tiny island of Sambawan on Friday, coastguard spokesman Armand Balilo said.

"The crew are detained aboard their vessel as the damage to the reef is assessed," he told AFP.

The ship was carrying logs from Malaysia to Japan when it hit the reef, Balilo added.

A central Philippines coastguard spokesman, Ensign Jamaal Aceron, told AFP the ship will be towed for repairs to a shipyard in the central port of Cebu once the extent of the damage on the vessel is determined.

It was the latest in a series of maritime incidents at protected Philippine reefs this year.

A US Navy minesweeper ran aground at Tubbataha Reef, a World Heritage-listed marine sanctuary in the southern Philippines in January, leading to fines for reef damage and the dismantling of the ship.

A Chinese fishing vessel also ran aground at Tubbataha in April, causing even more damage. The crew were arrested and charged for damaging the reef as well as for carrying endangered mammals.