MAIDUGURI, Nigeria

The Nigerian military forces have killed about 200 Boko Haram militants during a clearance and consolidation operation on in the volatile northeast region, an official said.

In a statement, Maj. Gen. John Enenche, coordinator at the Directorate of Nigerian Defence Media Operations, said troops also suffer some casualties in a reprisal during a successful operation against the militants at Alagarno, a Boko Haram enclave in Borno state, conducted on March 21-23.

He didn’t disclose the number of casualties the military suffered, however, three military officers confirmed to Anadolu Agency on condition of anonymity that about 20 soldiers and officers were killed.

In a statement, Nigerian President Mohammadu Buhari condemned the attack and said he was "deeply saddened" over the loss of the troops.

He said military troops were paying huge sacrifices in the northeast to ensure “terrorists do not succeed.” He assured their sacrifices would not go in vain.

The incident was the first major attack on the military forces this year by Boko Haram which has waged terror attacks in the West African country for over a decade.

Nearly 3 million have been displaced and over 50,000 killed in the violence, according to a report by the country's National Emergency Management Agency.