Nigerian blast kills policeman

Two bombs exploded in Nigeria\'s restive north on Tuesday, killing one policeman in the city of Kaduna, hit hard by a wave of attacks claimed by Boko Haram Islamists, police said. Two bombs were planted near a military checkpoint outside the main mosque in Kaduna\'s Unguwar Sarki area, police and residents said. After the first bomb went off, soldiers at the checkpoint discovered a second explosive device and called the police anti-bomb squad, Kaduna state police spokesman Aminu Lawan told AFP. \"We lost one of our men from the police bomb disposal unit. He died when an explosive device he was trying to defuse exploded, killing him on the spot,\" Lawan said, adding that no other casualties were reported. \"As if he knew what was going to happen, the policeman ordered everyone to move back and as he leaned to take the bomb out of the bag, it exploded with a bang,\" resident Abdullahi Isa said, recounting the officer\'s death. Boko Haram claimed responsibility for coordinated blasts that rocked Kaduna on February 7. One of those attacks was carried out by a suicide bomber who tried to drive a car packed with explosives into a military barracks. The military said the bomber was stopped before reaching his target and that he was the only one killed. In December, a powerful explosion hit Kaduna, killing at least eight people, wounding many others and destroying a number of houses and shops, but the cause has never been clarified. Boko Haram has claimed a series of both large- and small-scale attacks around Nigeria -- primarily in the north -- that have killed more than 200 people this year. The group\'s deadliest attack came on January 20, just north of Kaduna, in Nigeria\'s second city of Kano, which killed at least 185 people. Boko Haram has mostly targeted the police and other symbols of authority in Africa\'s most populous nation and top oil producer.