A rocket exploded at an Afghan government building near the U.S. embassy compound in Afghanistan's capital on Wednesday, but there were no known U.S. casualties, the State Department said. Spokesman Tom Casey said a large rocket landed near or hit the Communications Ministry in Kabul. The building is a few hundred meters from the back gate of the U.S. embassy compound. “All U.S. employees were accounted for and there were no known casualties,” he said. A U.S. military spokesman in Kabul told CNN that an Afghan security guard was injured in the incident, but he knew of no other casualties. Colonel Tom Collins downplayed the seriousness of the attack. “It's more harassment than anything else,” he said.