Scores of extremist militants were killed in anti-terror operations by the Nigerian military in the country's northeast region in the past two weeks, an official said on Thursday.

At least 22 terrorist spies, 11 militants, and three logistics suppliers were also arrested during the military operations held between March 25 and the early hours of April 7, Bernard Onyeuko, the spokesman for the military, told reporters at a press briefing in Abuja, Nigeria's capital.

Onyeuko said some 30 civilians, who were taken hostage by the Boko Haram and Islamic State West Africa Province (ISWAP), were rescued during the period.

Between March 28 and 31, airstrikes by the military had taken out a heavy stockpile of ISWAP weapons in their depots at Bukar Meiram, a town in the northeastern state of Borno.

The military official said offensive operations by the military had led to the retaking of the terrorists' stronghold of Ukba/Camp Zairo in the Sambisa Forest where some artillery guns, armored personnel carriers, trailers, and a large cache of arms and ammunition were also captured.

"The troops also destroyed terrorist enclaves, captured some terrorists, destroyed terrorists' improvised explosive making factory during the operations," Onyeuko added.

Boko Haram has been collaborating with ISWAP to establish an Islamist state in northeast Nigeria. The terror groups have also extended their attacks to other countries in the Lake Chad Basin.