JAKARTA - Indonesia's counter-terrorism police have arrested three people allegedly linked to the suicide bomb attacks in Jakarta which claimed five lives and injured 11 others.

The three, all from Bandung in West Java, are: Jajang Iqin Shodiqin, 56, Waris Suyitno, alias Masuit, 37, and Asep alias Abu Dafa (age not known), a police source told The Straits Times on Friday (May 26).

The source said the three men were arrested by the Densus 88 squad in three separate locations in West Java. Their link to the Jakarta bombing is not clear yet.

Jajang, who has a few aliases, had an active role in raising donations to help fund radical Islamic boarding school Darul Anshor.

The Islamic State in Iraq and Syria (ISIS) group has claimed responsibility for Wednesday's attack at the Kampung Melayu bus station in east Jakarta, which targeted police officers escorting a traditional parade of residents welcoming the fasting month of Ramadan.

Three police officers as well as the two suicide bombers died in the incident.

A separate police source told The Straits Times on Friday that the police were still working on identifying the second bomber.

The first suspected suicide bomber has been identified as Ichwan Nurul Salam, a 34-year-old man from Bandung.

Preliminary investigation had previously pointed to a militant named Solihin as the second suicide bomber. Solihin also had links to the Darul Anshor Islamic boarding school, the source said.

This story is developing.