A bomb killed 34 people in Baghdad's Sadr City Shia district today as Iraq's minority Sunnis began the fasting month of Ramadan, which US commanders said might see a rise in sectarian bloodshed.
The bomb - most likely a car bomb, according to police - struck near a tanker distributing kerosene for stoves in Sadr City, whose poor residents are the power base of cleric Moqtada al-Sadr and his Mehdi Army militia.
In addition to the 34 people killed, 35 were injured, many badly burned.
Sunni militants claimed responsibility, declaring the attack revenge for killings by Shia militia.
US commanders had warned for weeks that they expected a surge of violence to accompany the holy month, having observed similar patterns in previous years. Shias and Sunnis have separate systems for declaring Ramadan's start; Sunnis began observing it today and Shias are expected to begin on Sunday or Monday.
The Americans say they are determined to bring an end to sectarian killings in Baghdad, which have soared since an attack on a Shia shrine in Samarra in February. They have put in place a system of checkpoints and some fortifications around its perimeter, expected to be ready in the next few days.
In a six-week-old security crackdown in the capital, a division of 15,000 American soldiers has secured scattered neighbourhoods and is due to move into more. They say killings are fewer in the zones they have targeted. But violence in the city as a whole has worsened over the past two weeks, with hundreds of bodies found on the streets showing signs of torture and execution-style killing, and more frequent attacks on US troops.
A senior US military official said the American force in Baghdad is not big enough to secure the city on its own.
Among other violent incidents in the country, police in Tikrit said gunmen had beheaded nine people including some policemen after dragging them out of two cars in a nearby town. One American soldier and one Dane were killed by roadside bombs, and a US State Department contractor was killed by a rocket attack on a British-guarded compound in Basra.
The Iraqi Army said it captured a leader of the al Qaeda-allied militant group Ansar al-Sunna. Brigadier Qasim al-Moussawi told Reutersthat Muntasir al-Jibouri - held with two others overnight in a village near Muqdadiya, 80 km (50 miles) northeast of Baghdad - was Ansar's leader in Diyala province.
The group denied in an Internet statement that any of its leaders were captured.