Tokyo - Japan has arrested the captain of a Chinese fishing boat that collided with two Japanese coast guard boats near disputed islets in the East China Sea, causing anger in Beijing and reigniting territorial tensions.

China's Foreign Ministry lodged a "strong protest" against the captain's arrest on Wednesday, with Assistant Foreign Minister Hu Zhengyue summoning Japan's ambassador for the second time in two days, Xinhua news agency said.

Hu "demanded that the Japanese side immediately release the ship and crew members on board and guarantee their safety," Xinhua reported.

Tokyo has also lodged protests over the incident but Japan's top government spokesman called for calm while the prime minister said the matter would be dealt with fairly.

A group of about 30 people carrying Chinese flags held a brief demonstration outside Japan's embassy in Beijing, demanding Japan "get out" of the islands, but they soon ispersed.