A double bombing killed at least six people and wounded 20 Monday outside the Baghdad office of a government agency that cares for Sunni mosques and shrines, witnesses and a hospital official said. In the initial attack, a suicide bomber detonated his explosives at the entrance to the Sunni Endowment office in Baghdad's northern Azamiyah district, witnesses and an army official said. As people rushed away from the site, a second explosion - believed to have been caused by a roadside bomb - detonated just meters away. The dead included Riyadh al-Samarrai, head of a local US-backed armed group, said the witness, who is an employee of the Sunni Endowment. His account was corroborated by a member of the armed group, who gave his name only as Abu Omar, and by an Iraqi army official. Another witness, one of al-Samarrai's guards, said the suicide bomber walked up to al-Samarrai - a former police colonel - and embraced him before detonating his explosives.