KUALA LUMPUR - A GLOBAL maritime watchdog on Sunday warned seafarers to keep a strict watch for pirates off Malaysia's southeastern coast after a recent attack by knife-wielding Indonesians in the area.

On Thursday, a tug and barge carrying coal was attacked off the tourist resort of Tioman island in Malaysia's east coast state of Johor, in the South China Sea. No one was injured but cash and phones were stolen from the crew.

'There have been four attacks so far this year, all on almost the same location,' said Noel Choong from the International Maritime Bureau's (IMB) piracy reporting centre in Kuala Lumpur.

'We are advising ships to maintain a strict watch for pirates in a 100-nautical-mile radius off the area of attack,' he told AFP.

'An anti-piracy watch would prevent boarding because Asian pirates, once they know they are being watched, will leave for fear of being caught,' he said.

The Singapore-flagged tug, managed by an Indonesia company, was towing a barge carrying coal from Singapore to Thailand when it was intercepted and boarded by the 10 pirates.

Mr Choong warned that piracy cases in Southeast Asia - which has been on the decline - could escalate in the wake of a global economic crisis.

'Piracy was at an all-time high, especially in the Malacca Straits, after the 1998 economic crisis in the region, fueled by the economic hardships faced by communities in the area,' Mr Choong said.

The maritime corridor, which handles 30 per cent of all global sea transport, has traditionally been a piracy hotspot, but joint patrols run by Singapore, Indonesia and Malaysia have significantly cut attacks.

In the year to September there were only two pirate attacks in the Straits, the IMB reported, compared to 38 in 2004 and a peak of 75 in 2000. -- AFP