YAOUNDE - At least 143 Boko Haram fighters were killed in an attack on a military camp in Cameroon on Monday, a minister said, adding that it was the heaviest loss sustained by the Nigerian Islamist group in the country."The terrorists ... lost 143 lives and important warfare equipment made up of assault rifles of various brands, heavy weapons and bullets of all calibers," Minister of Communications Issa Tchiroma Bakary said in a statement."On the Cameroon side, we lost one life, the Corporal-Chef Bela Onana, as well as four wounded."It was not immediately possible to independently verify the toll from the fighting near the northern town of Kolofata.Cameroon's army determines death tolls either visually, or by counting the number of vehicles it destroys and estimating how many militants each vehicle carried, a senior official in Cameroon's Far North region told Reuters last month.Boko Haram, which has killed thousands in its bid to carve out an Islamic state in northern Nigeria, had also targeted Cameroon over the past year. Earlier this month, a man claiming to be the leader of the group threatened to step up violence in Cameroon unless it scraps its constitution and embraces Islam.