"Patrol troops have successfully repelled an ambush in Buratai community in Biu, a town in Borno state. The troops who fell into the ambush laid by the terrorists while on patrol, engaged the terrorists in a decisive fire fight killing four of them and capturing one alive," Xinhua quoted military spokesperson Maj Gen Chris Olukolade as saying.
The military repelled the insurgents' attempt to launch attack in Buratai and Kawuri areas of the state, he added.
"Also in Kawuri in Borno state, troops in a patrol have killed five terrorists in a shootout. The troops also captured two AK 47 rifles and two vehicles used by the terrorists."
Also, Olukolade said a key suspect in the terror bomb explosion that rocked Kabang community in Mubi, Adamawa state, has been arrested by troops who cordoned the area in swift response to the explosion.
At least 18 people were killed after a bomb exploded at a football viewing centre in Nigeria's northeastern state of Adamawa on Sunday evening.
The blast struck a crowd in Mubi town when people gathered at a public place to watch a televised football match.
Irked by Boko Haram's insurgency in the West African country, Nigerian President Goodluck Jonathan had, last Thursday, directed the security forces to launch a full-scale military operation to put an end to the impunity of the terrorists, adding the unity and stability of Nigeria, as well as the protection of lives and property, were non-negotiable.
He said the activities of terror groups in the country had caused debilitating pains and horror on the nation.
"The war against terror may be difficult, but the days of peace will come again," Jonathan said.
Boko Haram says it seeks to enshrine the Islamic Sharia law in the constitution of Nigeria.