BEIJING, June 26 (Xinhua) -- China urges India to immediately withdraw its border guards that have crossed the boundary and have a thorough investigation of this matter, a Chinese Foreign Ministry spokesperson said Monday night.

According to spokesperson Geng Shuang, Indian border guards crossed the boundary in the Sikkim section of the China-India border and entered the territory of China, and obstructed normal activities of Chinese frontier forces in the Donglang area recently, and the Chinese side has taken counter-measures.

The Sikkim section of the China-India boundary has been defined by treaties, Geng said, noting that the Indian government has repeatedly confirmed in writing that there is no objection.

China urges India to respect boundary treaties and China's territorial sovereignty to maintain peace and stability in the China-India boundary, Geng said.

In view of the above event, for safety reasons, China has to put off arranging the Indian official pilgrims to enter China at the Nathu La Pass, Geng said, adding China has informed India through diplomatic channels.

The Nathu La Pass sits 4,545 meters above the sea level and is wedged between Yadong County in Xigaze Prefecture, Tibet Autonomous Region, and India's Sikkim State.