At least 20 Iraqis were killed in separate violence on Sunday with attacks in the northern cities of Kirkuk and Tikrit leaving 14 dead, and two suicide attacks claiming the lives of six people in the towns of Balad and Mahmudiya. In a village south-west of Kirkuk, 250 kilometres north of Baghdad, Iraqi army forces launched an early-morning rocket attack on a militant gathering killing seven of them, according to police sources. The local forces were aided in their raid by US troops. One of those killed was a leader in the so-called Ansar al-Sunna Islamic group, one of the most violent Sunni insurgent groups that has been blamed for several killings and kidnappings across the war-ravaged state. At least 14 suspects were also rounded up in and around al-Oyoun village, west of Kirkuk, during an operation carried out by joint US and Iraqi military forces, the same source said. In the south and north of Kirkuk, a total of seven bullet-riddled corpses were discovered. The bodies' hands were bound, and according to local authorities, the victims remain unidentified. In another incident, seven policemen were killed in Tikrit, 180 kilometres north of Baghdad, when armed gunmen stormed into a roadside police centre and opened fire. The centre was on a road between Tikrit and Bayji, 20 kilometres away. Two more police officers suffered serious wounds, according to local authorities, while the police station itself suffered considerable damage. Following the incident, a firefight between security forces and armed residents of the area occurred. However, the attackers fled, reportedly to an area in the north of the nearby Lake Thirthar. Meanwhile, at least four Iraqi soldiers were killed and 15 injured in a suicide bombing outside a military checkpoint in Balad, 70 kilometres north of the capital, an Iraqi military official said. Deputy governor of Balad Amir Abdel Hadi told Deutsche Presse- Agentur dpa a suicide bomber driving a large truck blew himself up outside a checkpoint on a bridge linking Baghdad to Balad. Emergency teams and US forces were searching for more people under the rubble, Abdel-Hadi said. Human remains and mutilated bodies were found, the official said adding that the number of soldiers who were at the checkpoint at the time of the blast was not known. In a separate act of violence, two people were killed and seven - including two policemen - were wounded when a suicide attacker detonated a car bomb in Mahmudiya, 35 kilometres south of Baghdad, said local police sources. The incident occurred near an Iraqi police patrol. On another note, US-led coalition forces said they positively identified a "terrorist" killed in a September 3 operation south-west of Mosul as one of those responsible for a series of August bombings in Nineveh province that resulted in hundreds of casualties. Abu Muhammad al-Afri led al-Qaeda in Iraq's operations in Sinjar and was one of those responsible for ordering the August 14 truck bombings, which targeted the Yazidi population, according to the US military statement. The multinational forces reportedly killed al-Afri during a strike in a remote area southwest of Mosul, 400 kilometres north of Baghdad. Separately, the US military in Iraq said their forces killed six militants and detained 21 suspects during a two-day operation targeting al-Qaeda in Iraq's senior leadership operating in the northern belt around Baghdad. During their operation, ground forces found a weapons cache that included 25 mortar rounds, 30 high-explosive rounds, 5,000 anti-aircraft rounds and other ammunition. They also said they discovered four improvised explosive devices planted in the area. Over the two-day operation, the US-led coalition forces destroyed seven buildings believed to be used for insurgent activities. dpa str pa ch