Five people have been killed in Nigeria's northeastern Maiduguri after a bomb exploded during prayer at a mosque on Wednesday night, a police statement said. Police added that 35 people were injured in the attack, which it said is likely a suicide attack. Preliminary investigations further suggest that the incident may have been a suicide bombing, based on the recovery of fragments of a suspected suicide vest and witness statements recorded, while investigations are ongoing to establish the exact cause and circumstances, Nahum Daso, spokesperson for Borno state police command, said in the statement. Daso said police were conducting a sweep of the area in search of secondary devices. The Christmas Eve attack is the latest in a series of attacks in Nigeria's troubled northern region, where the country is battling multiple armed groups, including Boko Haram and its splinter group, Islamic State West Africa Province, among others. Several thousand people have been killed, with millions