Singapore called on Asia's top security forum today to give "full attention" to securing shipping lanes in the Singapore and Malacca straits, warning militants could be planning seaborne attacks.

Foreign Minister George Yeo said security agencies were "painting dark scenarios" of terrorists hijacking gas tankers and blowing them up to choke the waterways and cripple global trade.

He told the Asean Regional Forum (ARF) security dialogue in the Lao capital Vientiane there should be greater international cooperation to advance security in the Singapore and Malacca shipping lanes, among the busiest in the world.

While primary responsibility for patrolling the waterways belongs to the three countries surrounding the straits - Malaysia, Indonesia and Singapore, countries using the routes could help in other ways, Yeo said.

The Singaporean and Malaysian navies are considering conducting air surveillance of the straits and hoped Indonesia would join in, he said.

The three countries already conduct joint naval patrols of the narrow waterways.

Support M'sian proposal

Yeo urged international support for a proposal by Malaysian Foreign Minister Syed Hamid Albar for regular meetings on maritime security as well as Japan's offer for training to build maritime security capacity.

"The ARF should give this issue of maritime security its full attention," Yeo told the forum, which included Deputy US Secretary of Robert Zoellick and top diplomats from Southeast Asia, Russia, Japan, China, India and Canada.

Yeo cited an incident in March 2003 off the coast of Indonesia's Sumatra island in which pirates boarded a chemical tanker and steered it off course for about an hour.

He said many security agencies believed the incident "was a rehearsal for terrorism at sea."

Insurer Lloyds Joint War Committee had meanwhile put the Straits of Malacca on its list of war risk areas, resulting in higher insurance premiums for ships, the minister said.

In the event of an attack on its harbour, "Singapore, of course, will be devastated," Yeo said. "But the impact on global trade would also be severe and incalculable."

Singapore is one of the world's busiest ports. A quarter of the world's seaborne trade and half of its oil supplies pass through the Singapore and Malacca straits.