Indonesian police have arrested nine more militants in connection with a plot to strike during the ongoing election period.
Those nabbed include six men who had returned home after travelling to the Middle East to join the Islamic State in Iraq and Syria (ISIS).
National police spokesman Mohammad Iqbal yesterday said the suspects, aged between 24 and 45, are from a Jemaah Ansharut Daulah (JAD) terrorist cell in Central Java.
The JAD is a local militant network whose leaders have pledged allegiance to ISIS. Its members have mounted attacks on Indonesian soil in the name of the extremist group, which is also known as Daesh.
The nine men were rounded up by Indonesian counter-terrorism police Detachment 88 across East Java and Central Java on Tuesday.
The latest arrests follow intelligence reports of possible terrorist attacks at the release of the presidential election results next week.
Inspector-General Iqbal said there were indications the suspects were planning an amaliyah, or mission, using bombs on May 22 when the elections commission will announce the official vote count.
The senior police official yesterday also urged people not to gather to protest en masse in public. "It is going to be dangerous because they will attack the masses, as well as the authorities, with bombs," he added.
Voters in Indonesia went to the polls on April 17 to elect a president as well as their parliamentarians and local leaders.
The incumbent Joko Widodo is poised to be declared the winner of the presidential election, but mass protests by supporters of his only challenger, Mr Prabowo Subianto - who has refused to concede the race - are expected once the official results are out.
The police said earlier that they may have uncovered a plot by militants to set off bombs during street rallies expected to be held in the days ahead.
Nine other suspects with several homemade bombs and bomb-making materials in Bekasi and Lampung, among other places, were arrested last week.
Police Brigadier-General Dedi Prasetyo said on Thursday that unlike the suspects who were arrested earlier, the group nabbed on Tuesday had more field experience.
Six successfully travelled to join ISIS in Syria, where they took part in the conflict between 2013 and 2017, while another was intercepted en route by Turkish security forces and deported to Indonesia, twice.
"This means the perpetrators who were arrested (on Tuesday) have the experience, the ability, and are more militant than the perpetrators captured previously in Bekasi and Lampung," added Brig-Gen Dedi.
More than 32,000 troops are being deployed in Jakarta to beef up security in the capital ahead of the announcement of the election results.
The police said that aside from securing the elections, the ramping up of counter-terrorism operations was also aimed at preventing attacks during Ramadan.
This has become standard operational procedure in Indonesia following a suicide bombing in Solo on the eve of Idul Fitri in 2016.
Insp-Gen Iqbal said a total of 68 terror suspects have been detained during raids by Detachment 88 since January.
The recent arrests in Indonesia came hot on the heels of a series of raids against ISIS-linked terrorists in neighbouring Malaysia, stoking fears of a resurgence of terror cells across the region.
The latest analysis of counter-terrorism trends published on Thursday by the S. Rajaratnam School of International Studies noted that the territorial defeat of ISIS has shifted the epicentre of violence from Iraq and Syria to countries with an active presence of ISIS-linked cells or other insurgents or terrorists.
"The return of segments of these foreign terrorist fighters indicates an escalation of threats in their home countries as they come armed with operational skills and could possibly regroup, establish local cells and engage in violence," said the report.
