The special anti-terror unit of Indonesia has arrested six individuals on suspicion of planning a terror attack in Java and having allegiance to the terrorist organisation the Islamic State. Investigators have reportedly found bomb-making materials and a black flag similar to that of Islamic State’s during a series of raids across the island over the weekend.

The first arrest was made on Friday in the city of Banjar located West Java. Following the arrest in Banjar, the anti-terror squad carried out more raids across Java. During a raid in central Java on Saturday night, where the police found fertiliser, ball bearings, nails and electronic switches which are used to make bombs, ABC reported.

According to National police chief Badrodin Haiti, the anti-terror squad, Densus 88, acted after information was received from the Australian Federal Police and the US Federal Bureau of Investigation.

“These arrests were carried out because of indications these men were involved in a terrorist network,” police documents state.

The Australian reported that among the six people arrested are Asep Urip, 31, who teaches at an Islamic boarding school in Central Java and Zaenal, 35, a pupil of Urip. According to police, Zaenal was being groomed to carry out an attack.

“From early information, it’s known that Zaenal was a candidate for a suicide bombing in Jakarta to be conducted on New Year’s 2016,” written in police documents about the arrests.

The black flag with a text inscribed in it that appeared similar to the ISIS flag was found at Urip’s house. After detaining the teacher-student duo, the police arrested two more suspects having connections with the religious school as well as bomb makers in other parts of Java.

The fifth man was arrested in Semarang on Saturday after police found bomb making materials from his home.

Contact the writer at feedback@ibtimes.com.au, or let us know what you think below.