Pro-Chechen gunmen who took hostages in a luxury Istanbul hotel overnight surrendered their arms this morning, the state-run Anatolian news agency said.
Private news channels earlier said the gunmen had ended their action at 10.50 a.m. (08.50 a.m. Irish time).
Anatolian gave no details and there was no immediate confirmation from the Interior Ministry, which had ringed the hotel with gunmen armed with pump-action shotguns and automatic rifles.
There was no official word on how many people had been held at the Swissotel on the banks of the Bosphorus waterway, which divides Turkey's largest city of 10 million people.
The armed men had held guests and staff hostage after forcing their way in with guns firing in a protest against Russian military action in Chechnya.
The group fired off shots and rounded up staff and guests as they stormed the hotel.
Some television channels had said that around 60 hotel guests and staff were hostages. Swiss aviation conglomerate SAirGroup said there had been 600 guests at its Istanbul Swissotel property and that all were unharmed.
There were no signs that anyone had been injured and many people had been released before the gunmen surrendered.
A unsigned fax statement apparently from the gunmen's group said their action was aimed at ending "the bloody and dirty Russian attack on our homeland the Caucasus". It said it would announce more details of demands later but wanted to speak to the media and foreign diplomats.
The statement, carried by the NTV television news channel and a copy of which was seen by Reuters, also apologised to Turkey and Turkish tourism operators for "the loss of perhaps a few tens or hundreds of thousands of dollars".
"We will not shed blood," it said, warning that the group would not be responsible for any bloodshed in the event of a Turkish security forces raid on the hotel.
The attackers' appeal to Turkish authorities and pledge to make releasing Turkish hostages a priority appeared to conform to the stance of a pro-Chechen movement inside Turkey that has consistently won and played on widespread public sympathy.
"We cannot be described as terrorists. Despite the fact that we have been forced to limit the freedom of innocent people, to carry arms and to carry out an action that terrorises, we are definitely not terrorists," it said.