Police and hospital officials say the blast took place in southeast Baghdad today, a day after police in the area towed a suspicious car to the police station. The six killed were three bomb squad members and three policemen.
The officials spoke on condition of anonymity because they were not authorised to speak to the media.
Baghdad has for years seen near daily attacks targeting civilians and security forces by car bombs, suicide attacks and roadside explosions. The attacks are mostly blamed on Sunni militants.