SURABAYA (East Java province) - Four men were shot dead on Wednesday (May 16) after they launched an attack using samurai swords on the Riau provincial police headquarters in Pekanbaru, local media reported.
The attack comes as the Southeast Asian nation has been rocked by a series of deadly attacks on churches and a police station, involving multiple suicide bombings carried out by families, including young children.
The spate of attacks by militants left at least 28 people dead with dozens more injured.
Two officers were wounded while another was killed after one of the perpetrators tried to escape and crashed into the officer, he said.
The families have been linked to the local chapter of Indonesian extremist network Jamaah Ansharut Daulah (JAD), which police said was behind the attacks.
Security forces have arrested hundreds of militants during a sustained crackdown since the Bali bombing. Another man was arrested and four others were suspected to have fled the scene, it said.More news: Cambridge Analytica Being Investigated By Justice Department, FBI
All six bombers were killed, including the mother who was Indonesia's first known female suicide bomber.
Then on Monday in Surabaya, a family of five targeted a police station - four of them were killed but an eight-year-old girl survived.
"They had the same teacher and they regularly met for Koran recital every week", said East Java police chief Machfud Arifin.
In a message carried on its Amaq news agency, Islamic State has claimed responsibility for the attacks in Surabaya.
The attackers were members of the Negara Islam Indonesia (NII) which is affiliated with the IS group, the spokesman said.
The church and earlier police station attacks were likely motivated by the arrest of JAD leaders, authorities said.