More than 20 Iraqis have been killed and many others injured in a day of unrest across the war-torn country. Twenty people were killed and four houses were demolished on Monday by US air raid over al-Fakhirya village near al-Yusifiya, south of Baghdad, informed sources told Aljazeera. Elsewhere, an Iraqi was killed and seven others were injured in an explosion that also damaged a US vehicle in al-Radwania district, south of Baghdad. In other developments, four members of the Iraqi national guardsmen were killed and seven others were injured after their patrol was attacked by fighters on Baghdad International Airport highway west of the capital, medical sources told Aljazeera. Following the attack, US forces encircled the site while helicopters carried the dead and the injured to Yarmuk hospital in Baghdad. Another member of the Iraqi national guardsmen was killed and four others were injured in an attack against an Iraqi checkpoint in al-Ghalibya area, west of Baquba. **Children attacked*** Meanwhile, an Iraqi child was killed and eight others were injured, four seriously, when a US missile landed in the Abu Ghraib district west of Baghdad while the children were playing, informed sources told Aljazeera. Although Iraqi police sources say the missile was of US origin, US forces have not commented on the incident. Earlier, a mortar bomb exploded in the al-Adhamiya district of Baghdad on Monday, leaving one person dead and seven others injured, medical sources told Aljazeera. At the same time, a series of explosions rocked central Baghdad. Columns of white smoke rose near the Green Zone, the heavily-fortified area housing the US embassy and Iraq's interim government. **US marines ambushed near Falluja*** Seven marines were killed and eight wounded when their convoy was attacked the al-Saqlawiya area on Monday, a journalist based in Falluja told Aljazeera. Three Iraqi national guardsmen also died during the attack. "Two explosive devices detonated as a multi-vehicle convoy passed through the area," journalist Abu Bakr al-Dulaimi said, adding that two Humvees were destroyed in the blasts. "More than 100 soldiers have taken up rooftop positions in nearby buildings," said al-Dulaimi. As helicopters flew overhead, US soldiers sealed off the site in al-Saqlawiya, which is about 15km from Falluja. The latest deaths follow those of two US soldiers killed in a mortar attack near Baghdad, the American military said in a statement. The attack left 16 others wounded. **Pipeline ablaze*** Also on Monday, a natural gas pipeline in northern Iraq was attacked, an act that could affect power in several cities, a police officer said. The pipeline connects the Janbur fields with the Baiji power station some 70km to the south, said Colonel Muhammad Ahmad from the Oil Protection Police. The Janbur fields are 20km south of Kirkuk. Firefighters were able to extinguish the fire about half an hour after it started, he said. He added that experts from the company would replace the damaged pipeline within a day. The Baiji electricity station can generate up to 400 megawatts a day and supplies the northern cities of Mosul, Kirkuk and Tikrit, with power, Ahmad said. **PHOTO CAPTION*** US soldiers stand at the site of a massive car bomb attack on the outskirts of Fallujah, 65kms (40 miles) north west of Baghdad, Iraq, Monday Sept. 6, 2004. (AP)