Yaounde - Cameroon's military has launched a new operation to rid the country of Boko Haram militants "once and for all" and soldiers are prepared to storm one of the group's remaining strongholds in Nigeria, a military commander said on Thursday.The operation - code-named Tentacle - began this week and involves thousands of soldiers working with Nigerian soldiers on the other side of Cameroon's northern border, General Jacob Kodji said."We must flush them out and free our people once and for all," Kodji said, adding that soldiers were "determined" and prepared to move into Nigeria's Sambisa Forest, a stronghold of the Nigerian-based Islamic extremists. The forest has been targeted in a sustained aerial bombardment by the Nigerian Air Force this year.Northern Cameroon has suffered regular raids and suicide bombings attributed to Boko Haram for more than a year. A particularly deadly spate of attacks in January killed at least 57 people in 17 days, according to government figures.Nigerians displaced by Boko Haram have accused Cameroon's army of killing dozens of civilians in cross-border raids into Nigeria while in pursuit of Boko Haram - claims the Cameroon government has denied.On Thursday, Kodji said there was no reason to fear rights abuses against civilians during Operation Tentacle. "Our militaries are well trained and know just what to do now and tomorrow as they have done in the past."Cameroon has contributed to a regional force to wipe out Boko Haram that also includes Chad, Benin and Niger.Niger's interior ministry said in a statement on Wednesday night that six soldiers were killed in an ambush carried out by Boko Haram - the latest attack in the country's southeast region which borders its strongholds in northern Nigeria.