Phuket, Thailand  - Thai police on Thursday destroyed a motorcycle parked outside the venue for Asia's top security forum, causing a blast that raised security concerns among its delegates.

"The motorcycle was parked where it shouldn't have been, and when sniffer dogs were sent to investigate, they seemed to detect something suspicious," Thai Foreign Affairs Ministry spokesman Thani Thongpakdi said.

Police blasted the motorcycle with water cannon, creating a loud noise that sparked fears of an explosion at the nearby Sheraton Grande Laguna hotel, where the Association of South-East Asian Nations (ASEAN) Regional Forum was under way on the Thai island of Phuket.

Authorities later said they had found some traces of fertilizer on the bike, which might have put the sniffer dogs on alert. It was not clear whether the motorcycle's owner was compensated for his destroyed bike.

Phuket, 600 kilometres south of Bangkok, has been under tight security for the forum, which has drawn 26 foreign ministers, including US Secretary of State Hillary Rodham Clinton.

About 10,000 army personnel have been deployed on the island, which has been placed under the Internal Security Act, allowing authorities to halt protests and arrest suspicious characters.

Thailand, this year's host of the annual forum, had to cancel a summit between 10-nation ASEAN and China, Japan and South Korea on April 12 at the beach resort of Pattaya after anti-government protestors invaded the venue. (dpa)