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. Four US Soldiers Killed in Afghan Attack VOA News 24 July 2010 United States Marines and Afghan National Army soldiers walk in formation during an operation to clear the area of insurgents near Musa Qaleh, in northern Helmand Province, southern Afghanistan, 23 Jul 2010 Photo: AP United States Marines and Afghan National Army soldiers walk in formation during an operation to clear the area of insurgents near Musa Qaleh, in northern Helmand Province, southern Afghanistan, 23 Jul 2010 NATO officials say four U.S. soldiers have been killed in a bombing in southern Afghanistan, where international forces are stepping up the fight against the Taliban.  NATO's International Security Assistance Force said Saturday the four died following an attack involving an improvised explosive device, or IED, a weapon commonly used by the Taliban insurgency. No one yet has claimed responsibility for the bombing.  U.N. Secretary-General Ban Ki-moon said Friday the Afghan government's plan to take over the country's security by 2014, improve governance and fight corruption will be a long and challenging process. Mr. Ban made the comments while briefing the Security Council on an international donor conference he co-chaired in Kabul earlier this week on the future of Afghanistan. His spokesman, Martin Nesirky, said Mr. Ban was encouraged by the outcome of the conference, but added that words must be followed by deeds from both Afghan authorities and the international community. Some information for this report was provided by AFP and AP. .