In Assam, four Sashastra Seema Bal (SSB) jawans were killed, three others injured and another missing in an ambush by National Democratic Front of Bodoland (NDFB) militants on the Indo-Bhutan border in remote Sirklaijhora area in Chirang district on Monday. The incident took place when the SSB patrolling party crossed the area located in the outskirt of the Manas National Park. Police said around 20 heavily armed NDFB militants were involved in the dreaded attack. The SSB jawans also retaliated and the encounter lasted for around 20 minutes. The causality of the militants is not known. The injured SSB jawans have been admitted to hospitals at Bongaigaon. Meanwhile, police and para-military forces have launched a massive manhunt in the Indo-Bhutan localities to capture the militants.