Lagos - Nigerian troops have rescued 1 880 civilians from a Boko Haram redoubt in the restive northeast in the past week and arrested hundreds of insurgents, a military commander said on Wednesday.The Sambisa forest, covering about 1 300 square kilometres, is a stronghold of the notorious jihadist group, who kidnapped more than 200 schoolgirls in 2014."During our operations in the period 14 - 21 December 2016, a total of 1 880 civilians were rescued from Boko Haram enclaves," Major-general Leo Irabor said in a statement after a news conference in the northeastern city of Maiduguri on Wednesday. He said the operation was part of a military campaign launched last year to clear the area of the jihadists. Irabor added: "564 Boko Haram terrorists were arrested while 19 others surrendered to our troops. Also, seven suspected kidnappers and 37 foreigners were equally arrested."He said several Boko Haram fighters were killed and a cache of arms and ammunitions was discovered.Boko Haram seeks to impose a hardline Islamic legal system in Nigeria's mainly-Muslim north.It has been blamed for the death of at least 20 000 people since 2009. The rebellion has also displaced some 2.6 million people, sparking a humanitarian crisis in the region.Since early 2015, Nigerian military with the support of a regional force, have recaptured a swathe of territory from the insurgents.But sporadic attacks on soft targets have continued in the volatile region, including the use of female suicide bombers.