Alert troops on Tuesday foiled a major infiltration bid when they gunned down five heavily armed militants in Machil sector in Jammu and Kashmir [Images], a defence ministry spokesman said.

He said troops guarding the border noticed a group of militants sneaking into this side from Pakistan-occupied-Kashmir early on Tuesday morning under the cover of darkness.

When challenged and asked to surrender, the militants opened fire with automatic weapons. The troops retaliated and the encounter continued for several hours.

"Later, during the search operation, five bodies were recovered," he said adding, a large cache of arms and ammunition including five AK rifles were recovered from the slain infiltrators.

The security forces have now launched a massive search in the nearby woods, the spokesman said.

He said searches are being conducted to make sure there is no militant hiding in the area.

This was the second major infiltration bid by militants from PoK since the snow started melting.

Last month, six heavily armed infiltrators were killed when they entered into this side from PoK in Rangwar sector.

Officials believe there are about 69 camps where militants are being given arms training in the PoK.

They said more than 1,500 militants across the border are trying to sneak into this side.