Kuala Lumpur - Ten pirates wielding machetes and knives robbed a coal barge in waters off Kuantan on Malaysia's east coast, a news report said Friday.

The ship, which was travelling from Singapore to Thailand, was intercepted and boarded late Monday by the pirates, who travelled in two speedboats, district police chief Johari Jahaya said.

The pirates stole cash and mobile phones from the crew - who were mostly Indonesians - before vanishing without injuring anyone, Johari told the official Bernama news agency.

Crew members lodged a police report on the incident on Wednesday.

Johari said the pirates were believed to be Indonesians, based on their accents.

Police declined to give details of the vessel's origins.

Johari said the crew claimed they had lost 16 million rupiah (1.28 million dollars) to the pirates.

He added that the Malaysian maritime agency would work with marine police to investigate the incident. (dpa)