Indian troops are rushing to repair a border fence in Kashmir, badly damaged by the heaviest snowfall in decades, to prevent incursions by separatist guerrillas.

Last year, Indian Army engineers fenced off most of the so-called Line of Control, a 742km military line that divides Indian and Pakistani Kashmir, in an attempt to curb an influx of anti-Indian militants.

But the concertina wire barrier was damaged in several places after the heaviest snowfall in four decades in February, an Indian Army brigadier said.

"The terrorists can just walk over the fence, there is so much snow," said the brigadier, who didn't want to be named. The fence, which passes through inhospitable terrain, consists of rows of concertina wire, about 3m high, electrified and connected to a network of motion sensors, thermal imaging devices and alarms.