Twenty-eight people - mostly policemen - were killed and injured in a blast of an explosive-packed house in southern Mosul in Ninawa governorate, 405 km north of Baghdad. Gunmen detonated the house as a police-army force tried to storm into the house, an Iraqi security source said Sunday. Following the house bombing, several explosive devices were detonated, killing two policemen and one soldier and injured 20 security personnel along with five civilians, according to initial counting. The source said security forces sealed off the blast scene.