Turkey on Friday, July 10, detained 21 suspected members of the Islamic State group, including three foreigners, in a major operation in several cities including Istanbul, state media said, according to AFP.

Police detained the suspects in pre-dawn raids in several addresses in Istanbul, as well as Sanliurfa province near the Syrian border, southern Mersin province and Kocaeli province east of Istanbul.

The detainees are suspected of helping the jihadist group recruit people from Europe as well as helping them travel to Syria, the official Anatolia news agency said.

The foreigners, whose nationalities were not immediately clear, were planning to cross into Syria to fight for IS, which follows a fundamentalist version of Islam.

The operation appeared to be the largest one yet targeting IS suspects in Turkey, with arrests in the megacity Istanbul for the first time.

Arrest warrants were issued for at least 30 suspects, Anatolia said, adding that police also seized two hunting rifles, scores of bullets, documents belonging to IS as well electronic equipment and military uniforms.

Video footage showed bearded suspects with their right index finger pointing upward -- a gesture used by IS members referring to the unity of God -- as they were being led away by plain clothes police officers.

Asked by a reporter why they thought they were being detained, one suspect said: "Because you are kuffars (the infidel) targeting Muslims."

Another young man ironically said: "Because we're terrorists!"