The Turkish military said Friday it had sent troops into northern Iraq on Thursday night, in a limited operation to weaken Kurdish militants there. The military announced the operation on its Web site Friday, but Prime Minister Recep Tayyip Erdogan later played it down, describing the mission as "limited" in size and emphasizing that the soldiers would return to Turkey "in the shortest possible time."Reports of the numbers of troops varied. Reuters cited the Turkish foreign minister and an unidentified American official in Baghdad as saying that only a few hundred had been deployed, while Turkish television reported that about 10,000 troops had been deployed. In Baghdad, Rear Admiral Gregg Smith described the incursion as "an operation of limited duration to specifically target PKK terrorists in that region."