The Nigerian military says 19 soldiers have gone missing after the Boko Haram Takfiri terrorist group ambushed military forces in the embattled northeastern province of Borno.

On Thursday, “when our troops were returning to their defensive location, they ran into an ambush by the terrorists who came to reinforce their fleeing comrades. The troops fought back... killing many of them,” said Major-General Lucky Irabor, the military chief of staff, on Friday.

He went on to say that three officers and 16 soldiers were still missing, adding that another 16 soldiers and three pro-government civilian vigilantes sustained injuries in the incident.

The development came three days after the army conducted a full-scale operation in the restive province, killing at least 42 terrorists and rescuing 42 children and 38 women kidnapped by Boko Haram in Gangere village.

This also comes as military has reportedly rescued as many as 10,000 people from Boko Haram captivity this year.

On April 14, 2014, Boko Haram terrorists kidnapped 276 girls from their secondary school in the northeastern town of Chibok in Borno. About 60 of the girls managed to escape afterwards, but the fate of the remaining others is still largely unknown.

That mass abduction of female students by the terrorist group has shocked people around the world and brought global attention to Boko Haram’s militancy.

Boko Haram started its campaign of militancy in 2009 with the aim of toppling the central government in Nigeria. It has so far taken the lives of at least 20,000 people and forced over 2.5 million others from their homes.

The group has pledged allegiance to the Daesh Takfiri terrorists operating mainly in Syria and Iraq.

Boko Haram has spread its attacks from northeastern Nigeria into neighboring Chad, Niger and Cameroon.