At least 13 people were killed and 21 wounded in separate incidents in Iraq Thursday, while al-Qaeda militant disguised as a woman was arrested, Iraqi police and witnesses said, according to dpa. In Baghdad, six people were killed and 19 wounded during security operations aimed at clearing the Iraqi capital of illegal militant groups. General Qassim Atta, spokesman for the Baghdad operations, said in a statement that Iraqi forces killed three militants in Azamiya district, while three Iraqi police were also killed. He added that 19 other persons were wounded and 33 detained during security operations in Mahmoudiya, Taji and Abu Ghoreib areas. Atta said the Iraqi government would lift the vehicle curfew imposed in Baghdad's Shula district on Friday. A curfew in Shiite Sadr City area of east Baghdad will also be lifted on Saturday. US helicopters meanwhile continued to strike Sadr City, witnesses told Deutsche Presse-Agentur dpa. Loud explosions could be heard in Sadr City, a stronghold of the Mahdi Army of radical Shiite cleric Moqtada al-Sadr, which has been encircled by US and Iraqi troops since March 25. Intensive attacks were reported occurring Wednesday and lasting until the early hours of Thursday. There was no word as to the number of casualties. In Kirkuk, some 250 kilometres north of Baghdad, Iraqi police told dpa that five Iraqis were killed and two wounded in separate attacks across the city. In one incident, militants wearing police uniforms attacked a house in Kirkuk's Howija area in the early hours of Thursday. Two brothers were killed and their father was wounded in the attack, police sources said. A police officer and his nephew were killed when militants attacked them on their way to work in Jamila district in Kirkuk. Another civilian was killed when militants open fire at him near his house in Rashad area, southern Kirkuk, police said. Also in Kirkuk, Iraqi police arrested Ahmed al-Jowaly, described as an al-Qaeda militant, after he had been involved in kidnapping two engineers. Police detained Al-Jowaly, who was disguised in wome's garb, after finding the corpses of the two abducted engineers under a bridge in Kirkuk's Rahimao area. Sources said that Iraqi police detained another 13 militants in separate areas across Kirkuk. In another development, militants opened fire on houses in Askari district, killing at least two Iraqi boys.