Three more suspects have been arrested in connection with the twin bombing attacks on British targets in Istanbul last week in which more than 30 people were killed and hundreds wounded.
It was not immediately known what charges would be brought against the suspects, defence lawyer Mr Selahattin Karahan said on Wednesday. The state security court freed 15 others who were being held in the probe.
On Tuesday, nine people were charged with belonging to or aiding and abetting an illegal organisation in the investigation into the bombings at the British consulate and the Istanbul offices of London-based banking giant HSBC.
Eight people have also been charged with involvement in the bombings of two Istanbul synagogues five days earlier, and officials said several more were in police custody.
Turkish Prime Minister Tayyip Erdogan accused Britain of not sharing intelligence about possible future attacks with Turkish authorities after London said on Tuesday that "further attacks may be imminent" in Istanbul and the capital Ankara. Australia issued a similar alert yesterday.
A British Foreign Office spokeswoman told Reuters Britain conveyed information to countries where a threat occurred to reduce the risk of an attack. "We have been working closely with the Turkish authorities on counter-terrorism issues," she said.
Groups linked to Osama bin Laden's al-Qaeda network claimed responsibility for the November 20th suicide attacks on the British targets, as well as similar co-ordinated bombings at two synagogues in which 25 people died the previous week.