ISTANBUL, Feb. 10 (Xinhua) -- Turkish police on Saturday detained 31 foreigners suspected of links to the Islamic State (IS) in Istanbul, local media reported.

Anti-terror teams launched operations in six places in the city over tip-off that the suspects were planning a terror attack, the state-run Anadolu news agency said.

The police also seized many organizational documents and digital equipment during the raids, Anadolu said.

Turkey has been hit by a series of bombing attacks by IS militants over the last two years, and the country has been tightening operations against the group in recent months.