China on Tuesday upped the ante on the latest problem along its boundary with India in Sikkim and lodged a protest with New Delhi over transgression by Indian Army soldiers into its territory.

Beijing demanded that New Delhi must withdraw its soldiers from what it claimed to be territory of China. It also made it clear that Kailash Mansarovar pilgrims from India would not be allowed to enter China unless the Indian Army personnel were withdrawn from the area where its People's Liberation Army (PLA) soldiers were constructing a road.

The Embassy of China in New Delhi lodged the protest with the East Asia division of the external affairs ministry. The Chinese diplomats also lodged a similar protest with the Embassy of India in Beijing.

“Our position to uphold our territorial sovereignty is unwavering. We hope the Indian side can work with China in the same direction and immediately withdraw the personnel who have overstepped and trespassed into Chinese territory,” Lu Kang, a spokesman of China’s foreign affairs ministry, has said.

India is yet to respond to the allegation. Sources in New Delhi said Prime Minister Narendra Modi, who was in The Netherlands on Tuesday for the last leg of his three-nation visit, had already been briefed about the fiasco by National Security Adviser Ajit Doval and Foreign Secretary S Jaishankar.

A formal response might be issued, after Doval and Jaishankar, who are travelling with Modi, returned to New Delhi early on Wednesday.

China's border guards at Nathu La in Sikkim last week stopped pilgrims from India from crossing over to the Communist country for the annual pilgrimage to Kailash Mansarovar in Tibet.

The move came amidst reports that China’s PLA soldiers transgressed into territories of India at Doka La in Sikkim and destroyed some bunkers of Indian Army. Beijing on Monday alleged that Indian Army personnel transgressed into the territory of China and stopped PLA soldiers from constructing a road.

“The construction of the roads in Donglang (Doklam) area by the Chinese side is entirely a sovereign act in its own territory, and the Indian side has no rights to interfere,” Ren Guoqiang, the spokesperson for China’s Ministry of National Defence, said in a statement issued late on Monday.

Transgressions by the soldiers of India and China into each other's territory are often blamed on differences of perception about the alignment of the Line of Actual Control, which is considered the de-facto border between India and China in the absence of a settled boundary.

Beijing, however, ruled out any possibility of the difference in perception causing the alleged transgression by Indian Army.

“The China-India boundary in Sikkim has been delineated by historical treaties and the Indian government has repeatedly confirmed in writing after the independence of India, acknowledging that there is no objection to the trend of the China-India boundary line at the Sikkim section,” the spokesperson of China's Ministry of National Defence said on Monday.

Beijing on Tuesday admitted that it stopped the Kailash Mansarovar Yatra through Nathu La in response to the transgression by Indian Army.

“As to Indian pilgrims' journey through Nathu La pass at Sikkim section, I think the Indian side is very clear about this. For a long time Chinese government has made enormous efforts to provide the necessary convenience to those Indian pilgrims,” Lu, the spokesperson of the Ministry of Foreign Affairs of Chinese Government, was quoted as saying in Beijing.

“But recently the Indian border personnel trespassed Chinese border to obstruct our construction. We have taken necessary measures. Out of security consideration we have to put off the pilgrimage by Indians through the Chinese pass,” said Lu.

“We have to depend on what the Indian side will do. They have to take action to improve the security situation,” he added, when asked if the Chinese government will allow the pilgrims to enter its territory through Nathu La in future.