US troops fired on vehicles at checkpoints in Baghdad and northern Iraq, killing a child and at least four other people, the American military said Tuesday. The military also said it was checking a report that an American patrol fired on civilian cars near a Baghdad bridge, killing two Iraqis. Roadblock shootings have consistently fed anti-US sentiment among many Iraqis since the arrival of the American forces in 2003. US troops have been hit by suicide car bombs numerous times since 2003, and act quickly to protect themselves when a driver ignores orders to stop. The roadblock shooting in Baghdad took place Tuesday morning in a northern neighborhood known to be a Shiite militia stronghold as a minibus driver collected employees of the Rasheed bank, police said. US troops fired warning shots when the bus reached the checkpoint and tried to drive through, killing as many as four passengers - including three women, police and hospital officials said. "As I understand it, some of the warning fire ricocheted and may have killed two to three individuals," said Rear Admiral Gregory Smith, a US military spokesman.