Two CRPF personnel were killed and two others injured as militants attacked a camp of security forces in Manipur's Bishnupur district in the early hours of Saturday, police said.

The militants attacked an IRBn (India Reserve Battalion) camp at Naranseina in the Moirang police station area, they said.

"The militants fired indiscriminately from hilltops, targetting the camp. It started around 12.30 am and continued till about 2.15 am. The militants also hurled bombs, one of which exploded in the outpost of CRPF's 128 battalion," a senior police officer said.

The deceased were identified as sub-inspector N Sarkar, a native of Assam's Kokrajhar district, and head constable Arup Saini of Bankura district in West Bengal, he said.

The injured were inspector Jadav Das and constable Aftab Das, he said, adding that they received splinter wounds.

"The two injured personnel were admitted to the Regional Institute of Medical Sciences in Imphal. They are out of danger," the officer said.

The CRPF personnel were deployed to provide security to the IRBn camp.

A massive search was underway to find the perpetrators of the attack, police said.

Condemning the incident, Chief Minister N Biren Singh said, "Such actions demonstrate cowardice against dedicated security personnel who work tirelessly day and night to uphold peace and stability in the state. Their sacrifice will not go in vain."