Turkish police officers secure the area around the headquarters of a media company with alleged links to a government critic.

Turkish police detained 11 suspects in helicopter-backed raids targeting Islamic State of Iraq and Syria (ISIS) militants across Istanbul, the state-run Anadolu Agency reported on Thursday, just days ahead of a G20 summit being held in the country.

The raids were part of a series of operations against suspected militants in Turkey, where security is being tightened ahead of the world leaders’ summit being staged this weekend.

Last week, police detained 20 people suspected of links to ISIS in the southern resort province of Antalya, where the G20 summit is being held from Nov. 15-16.

The anti-terror squad police carried out simultaneous raids on more than 20 addresses in various districts of Istanbul, with seven foreigners among those held, Anadolu said.

It said the operation was continuing and more people might be detained.

Turkey vowed to take a more active role in combating ISIS in July. The radical militants control territory in Syria along the

Turkish border and have been linked to the suicide bombing last month of a pro-Kurdish rally in Ankara that killed more than 100 people.

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