'We will attack Nigeria again and again', Boko Haram leader vows The group also staged coordinated attacks on Christmas Day, the mostly deadly at a Catholic Church near Abuja where at least 44 people were killed. After a meeting with governors from 19 northern Nigerian states early Friday, Namadi Sambdo, Nigeria's vice president, denied that religious tensions were fuelling the Boko Haram menace in the country whose population is roughly divided between a predominantly Muslim north and a mainly Christian south. "It is very clear that there is no religious problem, religious fighting in northern Nigeria," Mr Sambo said. Elizabeth Donnelly, an Africa analyst at the London-based think-tank Chatham House, said such tensions do exist and that Boko Haram may be using them to increase their strength. "If they thought it was to their advantage, it would be quite easy for Boko Haram to exploit existing tensions," she said. In Kano, hit by a fresh blast on Thursday after armed men stormed a police station two days earlier, gunmen kidnapped a German engineer working with a Nigerian construction company Dantata and Sawoe. Edgar Raupach was seized by men who "came and handcuffed him and put him in the boot and zoomed away," said Kano police spokesman Magaji Majia. A foreign ministry spokesman in Berlin said "that we have to assume, from the situation, that a German national was abducted in north Nigeria." The kidnapping of foreigners is rare in northern Nigeria and there were no immediate indications that Boko Haram was linked to the abduction. The US Embassy in Nigeria meanwhile said a US citizen kidnapped in the country's southern delta earlier this month had been released.