China has cancelled events to commemorate 40 years of diplomatic relations with Japan, further signalling its anger over a simmering territorial dispute.

A Japanese foreign ministry official, Hiroaki Sakamoto, confirmed that China had cancelled the events, planned for Thursday. He did not provide further details.

China’s Xinhua News Agency, citing officials from the China-Japan Friendship Association and another government-affiliated group, reported on Sunday the events would not take place as planned. It said they would be held “at a proper time”.

Calls to China’s foreign ministry were not answered. In its evening broadcast, China Central Television said the timing of the events was being “adjusted”.

Relations have sunk to their worst level in years as the two sides spar over islands in the East China Sea claimed by both countries and by Taiwan.

In the latest large anti-Japan protest in China, up to 3,000 people demonstrated in Sunday in the southern city of Guangzhou, Xinhua reported.

A Chinese foreign ministry spokesman, Hong Lei, said in a statement late on Saturday that Japanese personnel had landed on the islands to stop Taiwanese activists from doing so and that China had protested strongly to Japan over the “severe infringement upon China’s territorial sovereignty”.

A group of Taiwanese fishermen have said they will sail 60 boats to the islands on Monday to protect their fishing grounds.

Hundreds of people marched in Taiwan’s capital, Taipei, on Sunday to protest against Japan for occupying the islands.

They waved anti-Japan signs and asked Tokyo to relinquish the islands, called Senkaku in Japan and Diaoyu in China.

Japan’s government bought several of the islands from their private Japanese owners this month, setting off angry demonstrations across China.

Taiwan’s government has maintained a cautious approach to the dispute to avoid straining ties with Japan.