An army jawan was killed and two others seriously injured when a powerful bomb, allegedly planted by insurgents, exploded in Manipur's interior Churachandpur district, bordering Myanmar and Mizoram, on Tuesday morning.

Official sources said personnel of 11 Gorkha Rifles were on patrol duty when the bomb, which was attached to a culvert, exploded at around 6.40 am, killing a jawan on the spot and injuring two others seriously.

It was not immediately known whether the suspected insurgents used a remote-controlled device or a timer.

The explosion occurred about 6 km from Churachandpur police station and about 50 km south of Imphal, the sources said.

Security and police personnel posted near Churachandpur police station immediately surrounded the area and launched a search operation. No one has been apprehended and it is suspected that the assailants might have hidden in the nearby thickly wooded hilly area.

No individual or group immediately claimed responsibility for the incident, which is the first major attack on army personnel this year, the sources added.