A Turkish news agency says police have detained 11 people suspected of al Qaeda links and seized 25 kilograms (55 pounds) of plastic explosives.
The private Dogan news agency said Thursday the suspects were rounded up in simultaneous raids in Istanbul and the northeastern province of Tekirdag. It said police found charts and photographs of the US Consulate, a synagogue and a church in Istanbul. Dogan didn't cite a source for the report.
Police in Istanbul and Tekirdag refused comment on the report.
Homegrown Islamist militants tied to al Qaeda carried out suicide bombings in Istanbul in 2003, killing 58 people.
In 2008, an attack blamed on al-Qaida-affiliated militants outside the US Consulate in Istanbul left three assailants and three policemen dead.