LAGOS, April 26 (Xinhua) -- Nigerian troops operating in the south region have killed two and arrested four gunmen of the Indigenous People of Biafra(IPOB), an outlawed separatist movement in the southern state of Imo, the army said on Tuesday.

       A group of gunmen from the separatist movement opened fire and launched grenade attacks on a patrol team of the army along the Orlu-Orsu road in the state on Monday, said Onyema Nwachukwu, the army spokesperson, in a statement on Tuesday.

       The patrol team responded with "superior firepower" and killed two of the gunmen, compelling others to flee in disarray, said Nwachukwu.

       "In a hot pursuit that followed the encounter, troops arrested four of the fleeing gunmen," he said.

       IPOB, founded by Nnamdi Kanu, the self-acclaimed leader of the group in 2014, seeks to create a group of states in south Nigeria to break away and form the independent nation of Biafra.

       The organization was tagged "illegal and amounting to terrorism" in 2017 by a Nigerian high court.