BREAKING NEWS » Multiple explosions have rocked Kano, the biggest city in northern Nigeria.~ The BBC's Yusuf Yakasai in the city says there is pandemonium with people running all over the place and plumes of smoke rising into the sky. One of the blasts hit the federal police headquarters in the city and two other police stations, he says. No-one has claimed responsibility for the attacks, but Islamist militants have been behind a recent campaign of violence in the mainly Muslim north. Our reporter says there is also a shoot-out going on at the police's state head office in the east of the city. The blasts targeted different neighbourhoods of the city. So far he is aware of explosions at the federal police headquarters in the west of the city, one police station in the centre, and another police station in the south. A reporter for the AP news agency said one of the explosions was powerful enough to shake his car several miles away from the blast. The Islamist Boko Haram group, whose name means "Western education is forbidden", wants to establish Sharia (Islamic law) in Nigeria and started to stage drive-by shootings in 2010 on government targets in its base in the north-eastern city of Maiduguri. It has stepped up its attacks in 2011, attacking the headquarters of the police and the UN in the capital, Abuja. In recent weeks, southerners, who are mostly Christians or animists, living in the north have been the targets of deadly attacks.