The attack came a day after the bombing of a key oil pipeline just east of the northern oil city of Beiji .
Saturday's explosion occurred at 9:30 a.m. at a police station about five kilometers (three miles) north of the city center, police said.
Beiji - which lies 250 kilometers (155 miles) north of Baghdad - houses northern Iraq's largest oil refinery, and serves as a key transfer point for crude oil being exported out of Iraq. Attacks on the Kirkuk-Beiji pipeline cluster have been infrequent in recent months, with some 300 U.S. soldiers and more than 2,000 Iraqi troops guarding the zone.
One hundred years ago today ended the most grueling of wars involving disgusting conditions for soldiers and at least 17 million deaths. We learnt nothing.
Russia has been developing an energy module on the basis of the megawatt-class nuclear power plant since 2010. The spaceship needs neither sunlight nor solar batteries