The long-awaited Baghdad security operation "is ongoing as we speak," the top US military spokesman in Iraq said on Wednesday. The Iraqi general who is leading the security drive took over the operation headquarters on Monday, but there had been no announcement until Wednesday that the sweep, the third attempt to crush violence in nine months, had begun. "It is ongoing as we speak," Maj. Gen. William B. Caldwell, the spokesman said. "The implementation of the prime minister's plan has already begun and will be fully implemented at a later date, having all the parts and pieces that he wants. "But portions are already being put in place, and we'll continue to put more into place as the forces arrive and the assets become available."