Gunmen fought in the streets of a mainly Sunni Muslim district of west Baghdad after dark today, residents and police said.
Police sources said gunmen had attacked a Shia mosque in Ghazaliya, a predominantly Sunni area close to another Sunni district where Shia militias killed over 40 people yesterday.
Other gunmen, apparently Shias, responded to the attack on the mosque, police said, leading to sustained gunbattles.
Earlier today Police said at least seven people were killed and 17 wounded in the blasts in east Baghdad, 200 metres apart near a telephone exchange in the Talbiya district.
Two car bombs blasted a Baghdad area that is a stronghold of Shia militia fighters today.
It is a bastion of the Mehdi Army militia of radical young cleric Moqtada al-Sadr.
The Mehdi Army militia has rejected accusations by minority Sunni leaders and police that it was behind yesterday's killings.
Those killings, the worst of their kind yet seen in the city, followed a car bomb attack on a Shia mosque in Jihad on Saturday evening and were followed in their turn by a double car bombing at another Shia mosque late on Sunday that killed 19.
Prime Minister Nuri al-Maliki has launched a national reconciliation plan to end the bloodletting between his fellow Shias and the once-dominant Sunni Arabs. President Jalal Talabani, a Kurd, appealed for unity.
Sadr, whose supporters have waged two rebellions against US forces in Iraq, blamed Sunday's violence on a "Western plan aimed at sponsoring a civil and sectarian war between brothers".