Earlier, a suicide bomber rammed his car into a bus carrying Oil Ministry employees as it passed a police academy in Baghdad, killing at least 10 people and wounding 30, police and witnesses said. âWe heard the blast. They died,â said a dazed survivor, who stood in a hospital as victims of the blast were wheeled in on stretchers. He told Reuters Television the bus was carrying employees of a state oil exploration company. Oil is the main revenue earner for Iraqâs battered economy, and energy infrastructure and staff are frequently attacked by insurgents. It was not immediately clear whether the bomber was targeting police or the Oil Ministry. Police were not able to say how many of the dead and wounded were police and how many were from the ministry. Oil Minister Ibrahim Bahr Uloum told reporters he believed the bomber had aimed the attack at his staff. âUnfortunately these terrorist operations continue to target innocents,â he said.