A Chinese surveillance mission to a disputed islands chain was “successful” in asserting Beijing’s sovereignty claim, state media said yesterday, following huge anti-Japanese rallies across China.

Two Chinese surveillance ship fleets arrived at the islands – called Senkaku in Japan, and Diaoyu in China – on Friday for “law enforcement” in the area, after Tokyo had nationalised the disputed archipelago days earlier.

The visit “demonstrated China’s jurisdiction over the Diaoyu Island and its affiliated islets, achieved the goal of demonstrating China’s sovereignty claim and ensured the country’s maritime interests,” Xiao Huiwu, deputy head of China Marine Surveillance told state-run news agency Xinhua.

Tokyo had on Friday summoned the Chinese ambassador to protest what it insisted was an incursion into territorial waters around islands it controls.

In response, China maintained the six boats that made up the surveillance mission were patrolling sovereign territory.

Japan’s coastguard on Friday said the ships were in the area around the islands for about seven hours.

Yesterday massive anti-Japanese demonstrations were held in cities across China, a day after an attempt to storm Japan’s embassy in the capital.

Beijing was infuriated last week when Japan said it had bought the rocky outcrops and while the authorities often suppress demonstrations, many of yesterday’s events took place with police escorting marchers, as state-run media called the protests “reasonable”.