More than 70 people have been killed after a bomb attack in a busy market in the Sadr City district of eastern Baghdad.Around 130 people were injured in the blast in the poor, mostly Shi’ite area. The bombing came four days after the US military formally handed control to local forces in Sadr City, as part of a plan to withdraw from Iraq’s main towns and cities. The attack is the latest in a violent week in Iraq. Scores of people have died in attacks in Baghdad and elsewhere. Under an agreement signed with the Iraqi authorities, most of the 133,000 US troops in Iraq are due to leave urban areas and withdraw to military bases by June 30. All US troops will be out of the country by the end of 2011.