BAGHDAD - A late night car bomb that tore through a cafe in Baghdad's Sadr City neighborhood appears to have detonated prematurely, killing three suspected militants riding inside, police said Thursday. The death toll from the blast, excluding the three suspected militants, rose to nine, according to police and medical officials, in what appears to be the latest attempt by militants to stoke a sectarian conflict by striking at a Shiite neighborhood with strong ties to militias. Police initially had said it was a parked car bomb, but subsequent reports revealed it was moving when it exploded and three bodies were found inside, suggesting they were headed to another target inside the densely populated district of at least 2 million. Police and hospital officials from the nearby al-Sadr and Imam Ali hospitals gave the death toll and details on condition of anonymity because they were not authorized to speak to the media. Sadr City is a stronghold of anti-American cleric Muqtada al-Sadr and the scene of blasts in April that killed 72 people. Following those blasts, al-Sadr offered Iraq's security forces the aid of his militia and there have been reports it is being revived. The Mahdi Army has clashed several times with U.S. and Iraqi forces since 2003 and was implicated in death squad-style attacks on Sunni civilians during the peak of sectarian violence in 2006 and 2007. Experts have said that the latest wave of militant attacks, including a coordinated series of strikes on Monday that killed 119 people across 10 cities, is aimed at provoking a militia backlash and reigniting sectarian fighting. The attacks came during a vulnerable period for Iraq.