JAKARTA (Reuters) - Indonesian police on Monday arrested five people in connection with a suspected militant attack on a church that killed one infant and injured three.

Police said they were investigating possible links to the Islamic State extremist group.

Sunday's attack in the parking lot of a church in East Kalimantan province on the island of Borneo was the latest in a series that has raised concerns over rising militancy in the world's largest Muslim-majority nation. An Islamic State-linked assault in the capital Jakarta in January killed four people.

Police said the attacker had been imprisoned on terrorism charges in the past and had links to existing radical networks.

(Reporting by Agustinus Beo Da Costa, Writing by Kanupriya Kapoor; Editing by Nick Macfie)