(KUNA) -- At least four people were killed and six were injured, mostly servicemen, when a suicide bomber blew up the car he was driving at a checkpoint in western Baghdad on Saturday, Iraqi police said.A source at the police told KUNA the suicide attacker detonated the explosives in the car he was driving at a check point jointly manned by Iraqi police and army. The bomb explosion killed four people, injured three policemen, two army soldiers and a civilian, said the source. The checkpoint is located at Al-Ghazaliya area in western Baghdad. The Iraqi forces cordoned off the area, banned cars and civilians from approaching, said the source. Meanwhile, the Iraqi police said a bomb went off in southern Baghdad today causing injuries to seven civilians.