The US and Turkey are to take part in a joint investigation over the US arrest of Turkish troops in northern Iraq, the State Department said late Sunday.
"US and Turkish military and civilian representatives are undertaking an investigation into the facts of the matter," State Department spokeswoman Amanda Batt said.
The Turkish news agency Anatolia reported Sunday that 11 Turkish troops arrested on Thursday had been released.
While the State Department declined to confirm the troops' release, it underlined that Washington and Ankara were "beginning a joint investigation involving US and Turkish military and civilian officials" into the incident.
"We are in close contact with our ally Turkey and we are making progress toward resolving this issue," Batt said.
The 11 Turkish soldiers were reportedly detained by US forces in northern Iraq on Friday.
According to a US administration official on Sunday, soldiers with the US 137th Airborne Brigade had detained 24 people in Sulayminah. The State Department confirmed nine as belonging to Turkey's special operations forces.
The group was detained on "suspicion of involvement in an alleged plot to harm Iraqi civilian officials in northern Iraq," the US official said. "Others were detained and subsequently released."
All 24 had been transported to Baghdad, the official added, saying no further details as to the detainees' nationality or identity were available.
According to Turkish news reports, the soldiers were to spend the night in a guest house in the Iraqi capital.
They were to be flown by helicopter back to the northern Iraqi town of Sulayminah yesterday where they were reportedly seized, the NTV television news channel said, quoting Turkish diplomatic sources.
The State Department said Sunday that US Vice President Dick Cheney had talked by telephone with Turkey's Prime Minister Recep Tayyip Erdogan.