AGARTALA, INDIA, AUG. 14 -- India and China have begun pulling back troops from the Himalayan border region, Indian Army intelligence officials said.

India has undertaken "partial demobilization" of its forces in its far northeastern state of Arunachal Pradesh, where it says Chinese troops have made repeated incursions across the border, the officials said yesterday.

They said the withdrawals have been made in the disputed Sumdorong Chu Valley, where China last year constructed a helicopter pad in a sector claimed by India.

The Chinese also have reduced their troop strength, they added, but they could not confirm that the helipad has been dismantled.

The withdrawals are part of an agreement by Army commanders to ease tensions before formal talks resume later this year in New Delhi.

Asked when the demobilization would be complete, the Indian officials said, "We are watching the Chinese moves and will go through our entire proposed withdrawal package once we are satisfied the Chinese are doing their promised bit."

Both countries are pledged to retreat to their main defense lines along the McMahon Line -- the British-drawn border between Tibet and India.

The border has remained tense since China and India fought a brief war in 1962.