China's Foreign Ministry on Thursday said India has been building up troops and repairing roads along its side of the border amid an increasingly tense stand-off in a remote frontier region beside Bhutan.

The stand-off on a plateau next to the mountainous Indian state of Sikkim, which borders China, has ratcheted up tension between the neighbours, who share a 3,500-km (2,175-mile) frontier, large parts of which are disputed. "It has already been more than a month since the incident, and India is still not only illegally remaining on Chinese territory, it is also repairing roads in the rear, stocking up supplies, massing a large number of armed personnel," the foreign ministry said. "This is certainly not for peace."