TEHRAN, Jan. 27 (Xinhua) -- Iranian security forces clashed with Islamic State (IS) militants in western Iran on Saturday, leading to the death of three Iranian forces and five IS militants, state IRIB TV reported.

The clashes came after 21 IS militants were found to infiltrate into the Islamic republic through the western borders, the report said without specifying the nationality of IS militants.

On Saturday, Mohammad Pakour, the commander of ground force of the Islamic Revolution Guards Corps (IRGC), confirmed the death of three IRGC members in the operation.

In the daylong clash, 16 IS militants were arrested, Pakour said.

A statement by the IRGC's Najaf Ashraf Base said the terrorist cell affiliated to the IS was identified through IRGC's intelligence activities, and the clashes erupted on Saturday morning, Tasnim news agency reported.

On June 7, 2017, six militants attacked Iran's parliament and Imam Khomeini mausoleum in the capital Tehran, killing at least 17 and injuring 52 others.

All the six assailants were killed, and the IS has claimed responsibility for the attack.