aid. At least four Afghans were killed. Five Italian soldiers were wounded, one of them gravely, Italian Defense Minister Ignazio La Russa said. Attacks around Afghanistan have been increasing since the Taliban announced their spring offensive, with strikes on Kabul, the main southern city of Kandahar and in the north. In the south on Monday, an Afghan wearing an army uniform shot and killed a NATO service member, the alliance said. NATO did not say exactly where the attack took place and it was not immediately clear whether the assailant was an Afghan soldier or a militant who had donned an army uniform to infiltrate NATO defenses. Previously, there have been cases of both. In Iraq, an estimated 46,000 U.S. troops remain stationed there though officials say combat operations are over in a nation that saw more than 4,400 American troops die in combat. Under an agreement between Washington and Baghdad, the troops still in Iraq must leave by Dec. 31. Black Hawk helicopters churned through the night sky Sunday as a strong wind coming over Kabul's surrounding mountains blew against the flickering candles that cast an orange glow on those gathered for a remembrance ceremony at the U.S. Army Corps of Engineers' headquarters. Earlier in the day, those working there enjoyed one of their five days off a year from building police stations, dams and other projects in a nation torn by decades of war. Col. Thomas Magness, 47, of Los Angeles, Calif., urged the more than 100 corps employees and U.S. troops gathered there to remember the meaning of Memorial Day — advice that could carry home to America. "While we were playing volleyball today, no doubt some soldier gave the ultimate sacrifice," the corps commander said. Memorial Day, instituted to honor America's war dead, will be observed Monday with a public holiday. This Memorial Day comes before the 10-year anniversary of the Sept. 11 terror attacks, which ultimately brought U.S. troops into Afghanistan to unseat the Taliban government and hunt terrorist leader Usama bin Laden. "Our country got attacked, and we're here to fight the war on it," said Roger Nowicki of the corps. While Navy SEALs shot and killed bin Laden earlier this month in neighboring Pakistan, the U.S.-led war here continues. President Barack Obama plans to draw down U.S. troops beginning in July, while NATO has committed to handing over control of security in the country to Afghans by 2014. In the meantime, the war grinds on toward its 10th year. The sharp pangs of loss are visible on some attending the event, like Maj. Erica Iverson, 33, of Vermillion, South Dakota. She spoke of serving as a casualty assistance officer after the 2010 death of Staff Sgt. Adam Dick