Nigeria’s military says its troops have repelled attacks by members of the Boko Haram militant group and killed 40 militants in the northeastern state of Borno.

The military said in a statement on Tuesday that militants “attempted coordinated and simultaneous attacks" on Sunday in three remote towns of Bama, Gwoza and Pulka.

Troops "successfully repelled all the attacks killing 40 terrorists in the three locations," the statement added.

On October 6, Boko Haram militants attacked worshipers in a mosque in Damboa town in Borno state and killed five worshipers who had come for performing the morning prayers.

The military forces then repulsed the militants and killed 15 of them.

Violence has intensified in northeastern Nigeria since President Goodluck Jonathan ordered his security forces in May to crush Boko Haram's four-year-old rebellion.

The Nigerian forces have been raiding militant camps and launching air and ground attacks on suspected hideouts of the militants over the past two months.

The military's newly formed anti-insurgency division has been taking part in the operations.

Boko Haram says its aim is to topple the Nigerian government, which it accuses of being pro-Western.

The group has claimed responsibility for a number of deadly gun and bomb attacks in various parts of Nigeria since 2009.

Over the past four years, violence in the north of Africa’s most populous country has claimed the lives of 3,600 people, including killings by the security forces.