Turkish police arrested 15 people on suspicion of ties with the extremist group Islamic State, Anadolu reports referring to the Istanbul police.

According to Turkish media, the group was detained for allegedly planning attacks on the Swedish and Dutch consulates in Istanbul, as well as on churches and synagogues. Istanbul police, however, noted that they were unable to establish any "specific threats" against those locations.

Intelligence that led to the police operation allegedly showed that the group may have received instructions from a certain branch of IS called the Islamic State-Khorasan Province, which operates in South and Central Asia.

Sweden and the Netherlands became centers of angry protests in Turkey after an anti-Muslim activist burned a Muslim holy book in Stockholm. A similar action took place in The Hague.

This week, a group of Western countries temporarily closed their consulates in Istanbul for security reasons. Turkish government officials accused them of failing to share information about the security threat that led to the closures and of seeking to harm Turkey.

In November, an explosion on Istanbul's busy Istiklal Avenue, located in the heart of the city and near several foreign consulates, killed six people and injured several others. Turkish authorities blamed Kurdish militants for the attack, but they deny any involvement.