ISIS plotted to use WIFI to remotely detonate backpacks full of explosives, as Indonesian police say they have rounded up dozens of skilled bomb-makers.

Indonesian police said Friday that they have arrested Islamic-State linked terror suspects, including some who planned to detonate bombs at political demonstrations when election results are announced next week.

Police said militants wanted to take advantage of any political unrest to spark chaos by using use WiFi to remotely detonate bomb-filled backpacks at crowded demonstrations.

'So we're urging the public not to go out on the streets on May 22 because it could be dangerous as they (the suspects) wanted to attack crowds and police officers,' a police spokesman told reporters in the capital Jakarta.

Suspected militants are escorted by anti-terror police officers shortly before a press conference at the police headquarter in Jakarta on Friday

Indonesian national police spokesman M. Iqbal (centre) shows the evidence including bomb-making materials and ammunition seized in the arrest of suspected militants during a press conference

Suspected militants are escorted by armed forces during the press conference after the police revealed the suspects' plans for carnage during the election results next week

Some 29 suspects were rounded up this month alone, with 60 in all detained since the start of the year in raids across the Southeast Asian nation, they said.

Eight other suspects had been killed in confrontations with authorities, police said, including the wife of a militant who blew up herself and a child following a dramatic standoff at their home in March.

Some arrested suspects were skilled bomb makers and had fought alongside the jihadist group in Syria, as well as members of local extremist network Jemaah Anshurat Daulah (JAD), police said.

JAD has pledged allegiance to IS and was blamed for a wave of suicide bombings at churches in Indonesia's second-biggest city Surabaya last year.

The world's biggest Muslim majority nation has seen a string of attacks by Islamist militants since the 2002 Bali bombings, which killed more than 200 people, including scores of tourists.

National police spokesman Muhammad Iqbal on Friday described the latest arrests as a 'preventative strike' before the official announcement of Indonesian elections, which were held on April 17.

There are concerns about street demonstrations after presidential challenger Prabowo Subianto, a retired military general, warned that protests could erupt over his claims of massive electoral fraud.

Indonesian Special Detachment 88 anti-terror police unit escorting terror suspects on Friday

The suspects were taken to the press conference with hoods on and handcuffs as the police announced they were aware of a plot to target the populace with bombs using WiFi

National police spokesman Brig. Gen. Muhammad Iqbal (centre) holds evidence as ammunition, explosive-making materials and other evidence were confiscated from suspected militants

Subianto has vowed not to recognise next week's results if they hand a re-election victory to president Joko Widodo, who has a lead of about 12 percentage points, according to unofficial polls.

Some 32,000 security personnel are expected to fan out across the capital next week, including in front of the General Elections Commission.

Subianto has attacked the Commission over allegations it was complicit in widespread electoral fraud.