"One of the explosions was a car bomb, but it was unclear what the other two blasts were," an unnamed official said.
Police said more than 50 others had been wounded by the blasts in east Baghdad. Two of the explosions were just 200 metres apart and near a telephone exchange in the Talbiya district. That district is a bastion of support for the Mehdi Army militia of radical young cleric Moqtada al-Sadr.
But the movement has rejected accusations, by Sunni leaders and police that it was behind yesterday’s killings, which saw bands of gunmen set up roadblocks and haul people with Sunni-sounding names from cars to shoot them. The attacks also killed people in streets and homes.
Al Sadr blamed that violence on a "Western plan aimed at sponsoring a civil and sectarian war between brothers".
The killings, the worst of their kind seen in Baghdad so far, followed a car bomb attack on a Shi'ite mosque in Jihad on Saturday, which was followed in turn by a double car bombing at another Shi'ite mosque late yesterday that killed 19.
Gunfire rattled across two Sunni neighbourhoods overnight.
This latest cycle of violence has again raised fears that Iraq is slipping into an all out civil war, despite a campaign launched by Prime Minister Nuri al-Maliki seeking national reconciliation.
President Jalal Talabani has appealed for unity.