NEW DELHI: China freed 10 Indian soldiers seized in a deadly high-altitude border clash in the Himalayas ahead of fresh talks Friday to ease tensions between the world's two most populous nations, officials said.

Two majors were among the troops held prisoner after a battle with nail studded batons, rocks and fists on Monday that left 20 Indians dead as well as an unknown number of Chinese casualties.

It was the most serious incident in more than four decades on the bitterly disputed unofficial border between the two nations, which have blamed each other for the confrontation and sent reinforcements to the area.

The release of the 10 soldiers late Thursday, confirmed by Indian security officials, followed several rounds of talks between top military officers and the foreign ministers on both sides.

India's government made no immediate comment but the army released a statement to say there were no remaining soldiers "missing in action" after the fighting in the Galwan Valley area of Ladakh.

Eighteen troops were being treated for serious injuries after the battle, the Indian military said. Security officials told AFP that four of them were in critical condition.

China has admitted that its forces suffered casualties but has not given figures.

Major generals from China and India were to hold new talks Friday, officials said.

Thousands attended funerals on Thursday for many of the 20 Indian soldiers killed in the clash.

Chinese flags and posters of China's President Xi Jinping have been burned in several cities.