Turkish legislators on Thursday renewed claims that American weapons have been turning up in the hands of Kurdish guerrillas staging attacks in Turkey.
US officials are preparing to investigate reports that weapons intended for Iraqi security forces were used in crimes in Turkey.
Earlier this year, Turkey complained to Washington about US weapons ending up with rebels of the Kurdistan Workers' Party, or PKK, who have been fighting for autonomy in southeast Turkey since 1984. The conflict has killed tens of thousands of people.
"The PKK is in possession of US weapons and they are smuggling them through the border into Turkey where they launch attacks on our military," said Saban Disli, a legislator and deputy chairman of Prime Minister Recep Tayyip Erdogan's ruling party. "The fact that this is being investigated is a very good sign."