"As part of their determined efforts to rid the society of all known Boko Haram terrorists enclaves and hideouts, troops... Conducted a fighting patrol along Damboa-Njaba-Bale road in Borno state" in the northeast of the country, Colonel Sani Usman said in a statement today.
He said the soldiers "killed three suspected Boko Haram terrorists (who) had been terrorising the communities around Sabon Gari and Damboa," on Sunday.
Usman said a cache of arms and ammunition was recovered from the jihadists.
He said a second encounter with the insurgents in Mainari village also on Sunday "led to the killing of nine terrorists and recovery of weapons which include four AK-47s and one pump action gun."
Nigerian President Muhammadu Buhari has given the military until the end of the month to crush the Boko Haram rebellion that has killed some 17,000 and forced 2.6 million to flee their homes since 2009.
The jihadist group, which seeks a hardline Islamic state in northern Nigeria, has also carried out deadly cross-border attacks in neighbouring Chad, Cameroon and Niger.