ISTANBUL (AP) — Turkey's police chief has said 100 people have been detained in raids against the Islamic State and that the group was allegedly planning an attack.

Police Chief Mehmet Aktas said Wednesday the suspects were detained in 26 raids across 21 provinces. They were allegedly preparing for a possible attack to coincide with Tuesday's celebrations marking the 96th anniversary of the founding of the Turkish Republic.

Turkey has stepped up security following IS leader Abu Bakr al-Baghdadi's death in a U.S. military raid in Syria. Police on Monday detained 20 foreign nationals suspected of IS links in a security sweep in Ankara.

Turkey was hit by a wave of attacks in 2015 and 2016 blamed on IS and Kurdish militants that killed over 300 people.