Turkish police detained 29 people with suspected links to the Al-Qaeda network in a pre-dawn swoop on Friday in three provinces, the Anatolia news agency reported.
Most of the suspects were rounded up in the southern province of Adana, while the others were detained in the country's biggest city Istanbul, Antalya on the Mediterranean coast and the western province of Canakkale, the agency said.
Police were still looking for two other suspects, it added.
The Adana police and local prosecutors were to question the detainees before releasing them or sending them to court to be charged.
Last week, police detained 28 Al-Qaeda suspects in a separate operation.
The Turkish police regularly target suspected Al-Qaeda supporters since two sets of twin suicide bombings hit Istanbul five days apart in November 2003.
A Turkish cell of Al-Qaeda was held responsible for the attacks, in which explosive-laden trucks first targeted two synagogues, and then the British consulate and a British bank, killing a total of 63 people, including the British consul.
Seven men were jailed for life in 2007 for the bombings, among them a Syrian national who masterminded and financed the attacks.