BEIJING — China and members of the Association of Southeast Asian Nations (ASEAN) have held their largest-ever joint maritime rescue exercise, signaling a lull in South China Sea tensions.

The drill on Tuesday simulated a collision between a Chinese passenger ship and a Cambodian cargo vessel off south China’s Guangdong province. It involved about 1,000 rescuers aboard 20 ships and three helicopters, according to reports in Chinese state media late Tuesday.

China, Thailand, the Philippines, Cambodia, Myanmar, Laos and Brunei took part, with Vietnam notably absent.

The exercise followed meetings between the Chinese and Singaporean defense ministers on the sidelines of the 11th ASEAN Defense Ministers’ Meeting in the Philippines last month.

China asserts sovereignty over almost all of the South China Sea in the face of rival claims from its Southeast Asian neighbors, including four ASEAN members.

It has rapidly reclaimed reefs, creating artificial islands capable of hosting military planes.

Disputes have sometimes spilt over into confrontations as vessels from the competing countries spar over fishing grounds and resource extraction.

But lately some have eased their opposition to China’s claims.

Last year a UN-backed tribunal, ruling on an application by the Philippines, rejected Beijing’s claims to most of the South China Sea.

Yet current Philippine President Rodrigo R. Duterte has refused to use the decision as leverage, softening his predecessor’s policy in favor of billions of dollars in trade and investment from the mainland.

Vietnam, however, has continued to deliver sharp rebukes. In June a meeting between Vietnamese and Chinese generals over border issues was abruptly cancelled, with both sides citing a sudden scheduling conflict.

Taiwan — which is not an ASEAN member — also claims almost the entire area, which is believed to sit atop vast oil and gas reserves. — AFP