kathmandu-At least four Boko Haram militants have been killed and several others injured in an ambush by troops in Nigeria’s northern state of Borno, a spokesman for the army said. Onyema Nwachukwu said in a statement reaching Xinhua on Thursday the troops laid the ambush on Wednesday after noticing the movement of the militants at a crossing point in the town of Pulka in Borno state. A fierce encounter ensued between the troops and militants, with the troops having superior firepower over them, Nwachukwu said. According to him, the troops also recovered a large cache of arms during the operation. The successful operation was “intelligence-driven,” said Nwachukwu, noting it was conducted with precision in collaboration with the government-backed Civilian Joint Task Force and local vigilantes. “Aside from the neutralized terrorists, several others escaped with injuries, leaving traces of blood behind, as the militants fled in disarray,” the spokesperson said. Boko Haram has been trying to establish an Islamist state in northeastern Nigeria since 2009. The terror group has also extended its attacks to other countries in the Lake Chad Basin.