Four soldiers were killed and one more was injured in an explosion at the base camp of the Nepali Army at Hatuwagadhi of eastern hilly district of Bhojpur on Monday.

According to the Eastern Regional Division of the Nepali Army, the explosion took place when a two-inch mortar shell buried at the periphery of the base camp exploded this morning. Officials said explosion took place when the soldiers were clearing the periphery of the base camp.

The injured solider has been taken to B P Koirala Institute of Medical Sciences at Dharan for treatment while the bodies of the soldiers have been air lifted to Kathmandu.

Officials say the two-inch mortar shell may have been buried during the attacks by Maoist rebels at the base camp on January 27 this year.

At least eleven rebels and two security personnel were killed during the overnight clashes.

The government and rebels are observing cease-fire now.