ISTANBUL, Dec. 31 (Xinhua) -- Turkish police on Monday detained at least four people over suspected bomb-making for the Islamic State (IS), local media reported.

The suspects, among them three Syrian nationals, were captured in raids in Turkey's northwestern province of Kocaeli, the Hurriyet daily said.

According to initial press reports, the detainees were responsible for making explosive devices and bombs for the IS.

Organizational documents and digital materials were seized as well in the operations, Hurriyet noted.

Over the past years in Turkey, more than 300 people were killed in deadly attacks blamed on the IS, including a mass shooting at Istanbul's Reina nightclub on New Year's Day 2017.