Nigeria’s military has rescued another set of women and children who had been kidnapped by Boko Haram militia and were being detained in Sambisa forest where the Islamist group has been holed up, an army spokesman said on Thursday.

Unlike the previous recovery, the army did not indicate the number of captives recovered.

Earlier this week, the army said it rescued nearly 300 women and girls from the same forest in the north eastern Borno state as it fights to quash the six-year Islamist insurgency.

“They have been evacuated to a safety zone for further processing,” Colonel Sani Usman said in a statement without specifying the number of people saved from the group, which seeks to create a caliphate in western Africa.

Several lives were lost including that of a soldier and a woman during shootouts in nine separate extremist camps in the Sambisa Forest, according to a statement late Wednesday from Usman.

He said eight women sustained gunshot wounds and four soldiers were seriously injured.

The army spokesman said several Boko Haram field commanders and foot soldiers were killed and combat tanks and munitions of high caliber used by Boko Haram were recovered while others were destroyed.

The group, whose name means “Western education is sinful”, has snatched at least 2,000 women and girls from their families since the start of 2014, according to Amnesty International.

Many of them have ended up as sex slaves or are used as human shields by the militants.

The uprising poses the greatest security threat to the country, but it was only the mass kidnapping of more than 200 schoolgirls from a school in Chibok a year ago that focused the world’s attention.

In the last two months, the Nigerian army has taken back control of swathes of territory in the remote north with the backing of troops from neighbouring Chad, Niger and Cameroon.

Nigerians hope president-elect Muhammadu Buhari, a former army general, will stamp out the rebellion which his predecessor, Goodluck Jonathan, struggled to confront