The Chinese Foreign Ministry on Friday denied that any Indian troops had been detained on the Chinese side.

"China hasn't seized any Indian personnel," said ministry spokesman Zhao Lijian, when questioned about Indian media reports about the soldiers' release.

An Indian government source was reported as saying that 10 soldiers had been returned after a confrontation on Monday in which 20 Indian soldiers were killed. No shots were said to have been fired at the time, with stones and batons reportedly used as weapons in the skirmish.

The Indian army also indicated that none of its personnel were ever in Chinese custody. It referred to an earlier Indian government statement that all of its soldiers had been accounted for.

Read more: Germany's Maas urges India, China to 'de-escalate' border tensions

China lays blame with India

Zhao claimed "the right and wrong is very clear and the responsibility lies entirely with the Indian side." 

But he added that the two sides were in communication over diplomatic and military channels. 

"We hope India can work with China to maintain the long-term development of bilateral relation," he told a daily briefing. 

The latest fighting in the Galwan Valley, part of the disputed Ladakh region, was the deadliest conflict between the sides in more than four decades.

Read more: How Chinese and Indian media reacted to border clashes 

Why is there tension at the border? 

Over the past few weeks, Chinese and Indian troops have been locked in aggressive posturing at multiple locations along the two nations' de facto border, known as Line of Actual Control (LAC), raising tensions between the two nuclear-armed neighbors. Thousands of extra troops from both sides have been deployed to the border zone in recent weeks. 

The tension might have been triggered by infrastructure activities carried out by India along the LAC, some analysts say. In the past 10 years, India has been boosting its border infrastructure, with new roads and airbases inaugurated in remote Himalayan areas. 

China claims about 90,000 square kilometers (35,000 square miles) in the Indian state of Arunachal Pradesh, referred to informally by some Chinese as "Southern Tibet." India, on the other hand, claims sovereignty over 38,000 square kilometers  of the Aksai Chin plateau. 

rc/rt (AP, Reuters)