Imphal, Nov 13 : In one of the deadliest extremist attacks in recent times in northeast India, militants gunned down an Assam Rifles Colonel, his family members and four jawans in Manipur's Churachandpur district along Myanmar border on Saturday, the police said. The police said the incident took place at around 11 a.m. near Sehken village, as the heavily armed suspected People's Liberation Army (PLA) militants fired upon the convoy of Assam Rifles Colonel Viplav Tripathi, killing him, his wife, their 9-year-old son, three Quick Reaction Team (QRT) jawans and the driver on the spot. The militants attacked the convoy when the Colonel of the 46 Battalion of Assam Rifles along with his family members was going to supervise a civic action programme in Churachandpur bordering Myanmar, which shares around 400 km unfenced border with Manipur. For the first time, the militants in the northeast killed the family members of a security force official. Though no militant organisation has claimed responsibility for the attack so far, the police and the intelligence officials suspect PLA cadres to be behind the heinous act. The Army, Assam Rifles and police forces led by senior police and para-military officials have launched a massive combing operation in the area to nab the militants. The location is an extremely remote village more than 130 km north of state capital Imphal. Defence Minister Rajnath Singh, Manipur Chief Minister N. Biren Singh, his West Bengal counterpart Mamata Banerjee, Director General of Assam Rifles Lt Gen P.C. Nair and many other people have strongly condemned the attack, which was perpetrated months before the next year's Assembly elections in Manipur. "The cowardly attack on an Assam Rifles convoy in Churachandpur, Manipur, is extremely painful and condemnable. The nation has lost 5 brave soldiers including CO 46 AR and two family members. My condolences to the bereaved families. The perpetrators will be brought to justice soon," Rajnath Singh said. Manipur Chief Minister Biren Singh, who had last week appealed to the militants to come to the negotiation table to sort out their demands, if any, said in a tweet: "Strongly condemn the cowardly attack on a convoy of 46 AR which has reportedly killed few personnel including the CO & his family at CCpur today. The State forces & Para military are already on their job to track down the militants. The perpetrators will be brought to justice." Manipur has over 40 outlawed insurgent groups, a large majority of them lying low following their signing of separate suspension of operation agreements with the government. In 2015, 20 para-military personnel were killed in an attack by terrorists in Manipur, after which the Army had launched a surgical strike on their camps. /IANS