Indonesian police said Saturday they killed six suspected members of a group loyal to Islamic State militants following a failed ambush of officers.

East Java Police Chief Machfud Arifin said late Saturday that the men were shot to death during an exchange of fire that ensued after they ambushed traffic policemen in East Java Province’s Tuban Regency.

None of the policemen was injured in the ambush Saturday morning or in the subsequent gunfight, he said.

The six were “clearly linked to the terrorist group Jamaah Ansharut Daulah,” he said. The group, formed in 2015, was designated by the U.S. State Department as a foreign terrorist organization three months ago.

It is made up of almost two dozen Indonesian extremist groups loyal to Abu Bakr al-Baghdadi, leader of the Islamic State, and is believed to have been behind a terrorist attack in central Jakarta in January 2016 that killed four people.

Machfud said the police also confiscated items including six firearms, a box of bullets, a passport, and four mobile phones, in connection with Saturday’s shooting, following the arrest of two suspected terrorists in the nearby town of Lamongan the previous day.

Indonesia, home to the world’s largest Muslim population, has been battling a growing terrorist threat and presence of Islamic State sympathizers. Bombing attacks in recent years included one on the resort island of Bali in 2002 that killed 202 people.