BEIJING (Reuters) - China said on Thursday it was absurd for India to use the excuse of Chinese road-building to cross over their border, and accused India of militarizing its side of the frontier.

A stand-off on a plateau next to the mountainous Indian state of Sikkim, which borders China, has ratcheted up tension between the neighboring giants, who share a 3,500 km (2,175 miles) frontier, large parts of which are disputed.

According to the Chinese interpretation of events, Indian guards crossed into China’s Donglang region early in June and obstructed work on a road on the plateau.

Troops from the two sides then confronted each other close to a valley controlled by China that separates India from Bhutan - a close Indian ally - and gives China access to the so-called Chicken’s Neck, a thin strip of land that connects India to its remote northeastern regions.

India has said it had warned China that construction of the road near their common border would have serious security implications.

Chinese Foreign Ministry spokesman Geng Shuang, speaking at a daily news briefing, again urged India to withdraw its personnel to the Indian side “to avoid there being an even more serious situation creating even more serious consequences”.

Geng said China did not understand what reason India had for believing the road was a security risk, and that China had every right to build roads in its own territory.

It was “ridiculous” for India to cross the border on the pretext of concern over the road, he added.

“Over the past few years it’s actually been India that has in the Sikkim sector of the China-India border who has been building a great number of facilities and deploying a large number of forces,” Geng said.

In some areas they have been building military facilities including fortifications, he added.

“I don’t know whether India has considered China’s security concerns while doing these things.”