At least 7 members of the Nigerian security forces are missing after insurgentsambushed their convoy

A team of 80 security agents tasked with protecting the electricity grid was ambushed onMonday in Shiroro, Niger State, by around 200 Boko Haram fighters during a patrol mission,Babawale Afolabi, spokesman for the Nigerian Security and Civil Defence Corps, said lateon Tuesday. At least 50 insurgents were killed, Mr Afolabi added.Among armed groups known for sabotaging Nigeria’s electricity supply is Boko Haram. Thenorth of the country was without power for more than seven days last month after insurgentsdamaged equipment, the state-owned Transmission Company of Nigeria said.Although Boko Haram operates mainly in the north-east of the country, the government saysthe group has cells in Muslim-majority Niger state, where its fighters ambushed the convoyand have previously carried out attacks on the army and civilians.The insurgent Nigerian group took up arms in 2009 to fight Western education and impose itsradical version of Islamic law, or Sharia. The conflict, now the longest-running struggleagainst militancy in Africa, has spread to Nigeria’s northern neighbours.According to the United Nations, some 35,000 civilians have been killed and more than 2million displaced in the north-eastern region. The abduction in 2014 of 276 schoolgirls byBoko Haram in the village of Chibok in Borno State – the epicentre of the conflict – shockedthe world.In late September, at least 100 villagers were killed in north-east Nigeria when suspectedBoko Haram fighters opened fire on a market, worshippers and homes, according to localresidents.