ANKARA (Xinhua) -- Some 21 suspected members of al-Qaida were arrested in a large operation in Turkey's largest city of Istanbul on Friday, the semi-official Anatolia news agency reported.

The detainees had all received military training in Afghanistan and prepared for terrorist attacks in Turkey, according to the report.

Al-Qaida-linked Turkish militants carried out a series of suicide bombings in Istanbul in November 2003, targeting British and Jewish interests in the city and killing some 60 people.