A Colonel of the Indian Army, his wife and eight-year-old son, and four Assam Rifles soldiers were killed in an attack in Manipur's Churachandpur on Saturday, officials said.
Colonel Viplav Tripathi was the Commanding Officer of the 46 Assam Rifles.
The officials said four others sustained injuries in the attack that happened around 3 km from Deheng locality.
Describing it as a cowardly attack, Singh said the perpetrators will be brought to justice soon.
"The cowardly attack on an Assam Rifles convoy in Churachandpur, Manipur is extremely painful & condemnable. The nation has lost 5 brave soldiers including CO 46 AR and two family members," he tweeted.
"My condolences to the bereaved families. The perpetrators will be brought to justice soon," Singh said.
Manipur Chief Minister N Biren Singh said the state forces and paramilitary troops are already on their job to track down the militants.
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"The perpetrators will be brought to justice," the chief minister said on Twitter.