Vietnam says armed Chinese soldiers forced their way aboard a Vietnamese fishing boat last week in the South China Sea and beat its captain, before forcing the trawler from an area claimed by both countries.

Vietnamese news reports quote coast guard officials as saying the encounter occurred July 5 near the contested Paracel Islands, whose reputedly mineral-rich waters are claimed by China, Taiwan and Vietnam. State media say the Chinese force confiscated about one ton of fish before forcing the Vietnamese boat from the area. Officials say the incident was not reported until the fishermen returned home Wednesday.

China has not commented on the report, which follows a spate of formal complaints from Vietnam and the Philippines alleging that Beijing has repeatedly violated established maritime procedure as it seeks to enforce its claims to the South China Sea and the Paracel and the Spratly island chains.

Beijing warned Vietnam last month that it was prepared to use military force, if necessary, to protect its claim over South China Sea. Five other governments: Brunei, Malaysia, the Philippines, Taiwan and Vietnam also claim part or all of the region.

In a related development, Japanese news outlets say China will be presented with a draft code of conduct for the South China Sea at a meeting of the Association of Southeast Asian Nations (ASEAN) in Indonesia next week.

Diplomats quoted by Japan's NHK television say the draft will address military exercises and exploration for natural resources, as well as appropriate responses to regional conflicts.

ASEAN and China agreed in 2002 to a declaration calling for the peaceful resolution of disputes stemming from overlapping maritime claims in the vast region. But efforts to negotiate a binding code of conduct have long been stalled, with China insisting the competing claims should be settled in bilateral talks with individual governments. Beijing has rejected calls, including those from the United States, for multilateral negotiations to settle the disputes.