New Delhi, Oct 5 (IANS): As the Indian Army holds its biggest ever mountain combat exercise 'Him Vijay' in Arunachal Pradesh, the first ever such drill in the northeastern state, it is reported to have irked China which considers large parts of Arunachal Pradesh as part of South Tibet.

Three battle groups, each comprising 4,000 soldiers, are participating in the exercise at a height of 14,000 feet, -- 100 kms away from the Line of Actual Control (LAC).

It is being carried out in phases in the upper reaches of Arunachal Pradesh near Tawang, and will end on October 25. The exercises are being held at a time when Chinese President Xi Jinping is to visit India for the second informal meeting with Prime Minister Narendra Modi, likely in Mahabalipuram.

Chinese Vice Foreign Minister Luo Zhaohui, who is here to oversee the visit of President Xi, is reported to have raised the issue during his meeting with Foreign Secretary Vijay Gokhale on Thursday.

The dates for Xi's India visit have not been announced yet.

His visit comes amid strains in India-China ties over the issue of Kashmir, with Beijing choosing to side with good friend Pakistan. Chinese Foreign Minister Wang Yi had also raised the Kashmir issue at the UNGA last week.

In this exercise, the capability of newly-conceived Integrated Battle Groups (IBGs) will be tested. The 'Him Vijay' will include troop mobilisation, mountain assault and air assault.

In February too, China had "firmly opposed" the visit of Modi to Arunachal Pradesh to inaugurate projects there.