A large blast rocked central Baghdad near the Iranian embassy on the outskirts of the Iraqi capital's heavily-fortified Green Zone as a landmark Arab summit opened Thursday, an AFP journalist said.
The blast was heard at around 1:40 pm (1040 GMT) and took place in the Salhiyeh neighbourhood of central Baghdad.
As smoke billowed into the sky, security forces members, military vehicles and firefighters were seen heading to the site of the blast.
The blast came despite strict security measures by the Iraqi government, which had 100,000 security forces members on alert in Baghdad, and effectively locked down the city, closing swathes of roads, shutting down air space and cutting mobile phone networks.
It came as the the first Arab summit to be held in Iraq in 22 years opened in the former Republican Palace in Baghdad.