On Wednesday, another national police spokesman, M. Iqbal, said the force had raised its level of internal monitoring. Both policewomen had been fired for violating the police code of ethics for deserting the police force. They will now be dealt with by the judiciary for the alleged terror activities, he said.

Dedi, who briefed the media at length on Tuesday, said at least 10 home-made pipe bombs, chemicals for use in explosives, air guns, knives, documents on planned attacks, jihadist books, laptops and cellphones were seized in the raids.

The suicide bombers were intending to use “high explosives” including a toxic poison called Abrin. The substance is found in the seeds of the rosary pea, a plant common in tropical areas, and has been described as a potential agent for chemical terrorism by the US Center for Disease Control and Prevention.

“These bombs are different from those usually assembled by terrorist groups. These ones are more dangerous with less than 0.7 microgrammes of abrin being able to kill 100 people,” Dedi said.

Indonesian authorities are on high alert after episodes of mass unrest across the sprawling archipelago in the last few months, with student protests against new laws last month resulting in clashes with police and the deaths of three youngsters.

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But State Intelligence Agency spokesman Wawan Purwanto said large demonstrations could be used by militants as cover for an attack, according to comments reported by Agence France-Presse.

Authorities have increased their scrutiny of JAD, which was founded in 2015 and gained notoriety after a January 2016 gun and suicide attack in downtown Jakarta that left eight people dead.

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Dedi said among the 29 arrested suspects were a man and his 14-year-old son on the tourist island of Bali who plotted to make a bomb for an attack against the local police.

Another character who went by the nom de guerre Jack Sparrow – a fictional character from the Pirates of the Caribbean film series – was detained for plotting to carry out a bomb attack in the restive Indonesian province of Papua.

Robi Sugara, a lecturer and counterterrorism analyst at Syarif Hidayatullah Islamic University, said what was “most worrying” was that terror groups would use knife attacks on any official, especially district level officials.

Benny Mamoto, a retired inspector-general of police who investigated many of the country’s major terror attacks, said the attack on Wiranto showed there was a need to “increase the level of alertness against attacks using sharp objects”.

Mamoto, who is now head of research for Police Study and Terrorism at the University of Indonesia, said the country’s standard operating procedures for security also needed to be re-evaluated.

“The SOP needs to be evaluated each time there is a change in the modus operandi of the threats and the form of attacks. This issue will continue to grow in line with global developments, especially if they [Indonesian terror groups] are affiliated with groups in a particular foreign country.

“Terrorists study the way the security apparatus works, including how they carry out their operations and their weaknesses, which then become an opportunity,” he said, adding that this was why security forces needed to stay one step ahead and anticipate threats from new types of attacks.