Nigeria's military has said it overran 10 Boko Haram camps in the group's Sambisa Forest stronghold, a day after the armed group attacked a crowded bus station in the northeast, killing seven.

Defence spokesman Chris Olukolade said late on Sunday that a number of rebels were killed in the offensive in remote Borno state, while one soldier died in a landmine explosion and two others were injured.

"The operation to clear the terrorists in Sambisa and other forests is continuing as troops in all fronts have been alerted to be on the lookout for fleeing terrorists," Olukolade said in a statement.

"The Nigeria Air Force is maintaining an active air surveillance to track the movement of terrorists for appropriate action as the operation continues."

On Saturday, seven people were killed and scores injured at a bus station in the Yobe state capital, Damaturu, which has been hit repeatedly during the armed group's six-year fight.

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The attack again indicated the rebels' ability to strike so-called "soft targets" and its persistent threat to civilians, despite claimed military gains in seizing captured towns and territory.

Nigerian troops have been seen as having the upper hand since February because of assistance from armies in neighbouring Chad, Niger and Cameroon.

Village raids

But on Friday, the deputy governor of Borno state said the strategic town of Marte, near Lake Chad where the four countries meet, had again fallen into Boko Haram hands.

At least 55 people were killed last week in two raids on villages near the Borno state capital, Maiduguri - the first attacks in and around the city for three months.

Olukolade said in a separate statement that Marte had been "deserted", with no military presence for "quite some time" because of the push against the fighters in Sambisa Forest.

"Now that their [Boko Haram's] presence is reported, the issue will definitely be addressed in a very short while," he added.

Nigeria's President Goodluck Jonathan is keen to announce that the armed group has been cleared from the northeast before he leaves office at the end of the month.

But experts have warned against any premature declaration of victory, with the root causes of the conflict, particularly chronic social and economic deprivation in the region, yet to be addressed.

Source: Agencies