SHANGHAI (REUTERS) - China has called for the swift return of a soldier it says is being held by Indian authorities after disappearing along the border.

The China Military Online, a news portal run by the military's official PLA Daily, said on Saturday the Chinese border guard went missing on Friday (Jan 8).

After the Chinese side reported the incident to India, India replied to say it had found the soldier and would hand him back once it had received instructions from more senior officers, according to the news outlet.

China Military Online added that Indian authorities should"promptly transfer" the soldier back to China and "jointly maintain peace and tranquility in the border area".

Tensions flared between China and India last June when a clash along the disputed Himalayan border led to the death of at least 20 Indian soldiers.

In the following months, the nuclear-armed neighbours deployed tens of thousands of soldiers across India's Ladakh region and China's Tibetan plateau.

In November, the two sides began formulating a disengagement plan to withdraw troops and establish no-patrol zones.