A suicide bomber struck the funeral of two anti-al-Qaida Sunni tribesmen in a town north of Baghdad on Thursday, killing at least 50 people and wounding dozens, police said. The blast was the latest this week to break a period of relative calm in Sunni areas, raising concerns that Sunni insurgents are reorganizing at a time when US and Iraqi troops are battling Shiite militiamen elsewhere. Over the past months, Sunni insurgent violence has eased with the increase in US troops and the growth of so-called Awakening Councils, groups of Sunni tribesmen and former insurgents who have joined American forces in fighting al-Qaida-linked militants. Thursday's attack took place in the town of Albu Mohammed about 150 kilometers north of Baghdad, during the funeral of two brothers who belonged to the local Awakening Council and had been killed in an attack a day earlier, police said. The suicide bomber walked into a tent crowded with mourners in the village and detonated explosives strapped to his body, police in the nearby city of Kirkuk said.