Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Coalition Forces Push on in Afghan Offensive VOA News 15 February 2010 U.S. Marines point their rifles, scanning for Taliban fighters as they cover the departure of a U.S. Army Pegasus medevac helicopter which picked up a wounded Marine from their unit, in Marjah, Photo: AP U.S. Marines point their rifles, scanning for Taliban fighters as they cover the departure of a U.S. Army Pegasus medevac helicopter which picked up a wounded Marine from their unit, in Marjah, Helmand province, southern Afghanistan, Saturday Feb. 13, 2010. U.S. Army Task Force Pegasus aero-medical crews are are supporting U.S. Marines who are taking the Taliban-held town of Marjah in a major offensive to break the extremists' grip over their southern heartland and re-establish government control. (AP Photo/Brennan Linsley) U.S.-led forces in Afghanistan pressed forward Monday with a major offensive to clear Taliban militants out of their last major stronghold in the southern province of Helmand. Some 15,000 U.S., British and Afghan troops are involved in operations centering on the town of Marjah, in the biggest joint-operation since the war began in 2001. Efforts to win the support of residents in the area suffered a major setback Sunday when two rockets fired by coalition forces missed their targets, accidentally killing 12 Afghan civilians. NATO took responsibility for the incident. Top commander U.S. General Stanley McChrystal conveyed his apologies to Afghan President Hamid Karzai, who ordered an investigation into the deaths. McChrystal also suspended use of the rocket system involved. Afghan officials say at least 27 insurgents have been killed during the fighting, while one U.S. and one British soldier were killed Saturday, the first day of the offensive. Some information for this report was provided by AP, AFP and Reuters. .