(AFP) Pirates have hijacked two ships in Indonesian waters and are holding one of the captains for ransom, the police said today.

Muhamad Muda, marine police commander, disclosed the two incidents as international experts began a two-day meeting on ways to fight Asia's piracy scourge.

Muhamad said the Indonesian-registered Tirta Niaga was attacked and its crew overpowered last night after it set sail from Malaysia's northern port of Butterworth pier, carrying palmoil bound for India.

"The pirates have kidnapped the Indonesian captain and are holding him on land for ransom somewhere in (Indonesia's) North Sumatra while the remaining 20 crewmen are on board the ship," he said.

The Malaysian-registered MT Selayang, which had sailed from Port Dickson in Malaysia with a cargo of gas oil used in diesel engines, was attacked near Borneo island on June 19.

The incident was only reported last Thursday, Muhamad said.

Prized commodity

The marine police chief said the pirates are still on board the vessel, adding that diesel oil was a prized commodity. It is not clear how many crew are on board the Selayang.

Muhamad said his officers are tracking both ships and have asked Indonesia for help. The Selayang is presently somewhere off eastern Borneo while the Tirta Niaga is drifting near Sumatra's north coast.

The two incidents drew immediate condemnation from the British-based International Maritime Bureau.

"There is an increasing problem of violent attacks," its director PK Mukundan said. "Piracy has to be taken seriously. We need to resolve the problem.

"They (countries in the region) have to allocate the resources to deal with it. They cannot close their eyes to this problem."

In May the IMB's Kuala Lumpur-based Piracy Reporting Centre said that worldwide actual or attempted piracy attacks from January to March this year hit a 10-year quarterly high of 68.

Indonesia accounted for 23 incidents and nine more occurred in the busy Malacca Strait separating it from Malaysia, it said in a report.