Officials display some of the evidence police collected during the arrests of terror suspects in Palangkaraya and Gunung Mas in Central Kalimantan earlier this week. (Antara Photo/Rendhik Andika)

Jakarta. Police detained 34 people in Central Kalimantan on Tuesday for their alleged involvement in plans to carry out a suicide bomb attack in Jakarta, an official said.

Several items, including bomb-making material, were seized during the arrests in two separate locations.

Fifteen people, including four women and five children, were arrested in Palangkaraya, the provincial capital, and the remainder in Gunung Mas district. At least two, identified by the initials T., alias Tomi, and A., are fugitive members of Islamic State-affiliated Jamaah Ansharut Daulah (JAD).

Among the four women arrested in Palangkaraya is the third wife of Abu Hamzah Hussain, a JAD member arrested in Sibolga, North Sumatra, in March. One of his wives denotated a bomb, killing herself and her two children, when police tried to arrest her at their home.

"They were in so-called uslah, or exile, while preparing [for their next operation]. They conducted training, which, based on reports, included archery, and gathered funds through farming activities and illegally mining for gold," Central Kalimantan Police spokesman Chief Comr. Hendra Rochmawan told Metro TV on Wednesday.

Gunung Mas is known for its rich gold deposits and many illegal mines are found in the district.

Hendra said the terror suspects are residents of Aceh and Sulawesi and were invited by one of the two suspects, identified as Anshari. Those from Aceh were part of a JAD group that managed to escape raids by the National Police's elite counterterrorism unit, Detachment 88, in the Gunung Salak area at the end of 2018.

"They were ready to depart for Jakarta, just waiting for a command, because they had sufficient training and funds," the police spokesman said.

"From the information we have gathered, they wanted to conduct an 'action against the democratic system' in Jakarta," Hendra added.

Police previously uncovered a plot by JAD members to use the rally by supporters of losing presidential candidate Prabowo Subianto against the result of the 2019 election as a cover to launch attacks, mostly targeting police officers.

The rally in front of the offices of the Election Supervisory Agency (Bawaslu) in Central Jakarta on May 21 ended in a riot, which continued in the following days. Nine protesters were killed in the riots, but the National Commission on Human Rights (Komnas HAM) said the bullets found in victims' bodies were different from those issued to police.

Hendra said the women who were arrested are the radicalized wives of terror suspects. Police are evaluating the children to determine whether they have also been affected by the terror group's doctrines.

Hendra said the series of arrests in Central Kalimantan was linked to the arrest of four terror suspects in Bekasi, West Java, on Tuesday.