JAKARTA - Indonesian police have arrested a total of 37 suspects in connection with the suicide bombings in Surabaya last month, said the country's top cop Tito Karnavian.
Four other suspects were shot and killed by police in the dragnet to bring to justice those responsible for the May 13 attacks on three churches, as well as one on the local police station in Indonesia's second largest city the next day.
"We moved fast after the suicide bombings... and identified the perpetrators," said General Tito, adding that the swift response by the police should continue to give the public a sense of security.
He was speaking to reporters on Thursday night (May 31) after breaking fast with Indonesian armed forces chief Hadi Tjahjanto during their visit to the Surabaya police headquarters.
The police chief did not reveal the identity of the suspects but confirmed that they were linked to the coordinated suicide bombings in Surabaya mounted by two separate families, and a plot that was botched by a third family in nearby Sidoarjo after their bombs exploded prematurely.
A total of 27 people were killed in the attacks, and among the dead were the 13 perpetrators, purportedly from sleeper cells of the Jemaah Ansharut Daulah (JAD), a local terrorist group loyal to the Islamic State in Iraq and Syria (ISIS).
Traces of military-grade explosives found at the scene, and women and children being used as cover for the suicide bombings, suggested a rising level of tactical capability in Indonesian terrorists.
The incidents in Surabaya, which occurred days after a hostage situation at a police detention centre housing JAD detainees, has since led to amendments to Indonesia's anti-terror laws, designed to prevent terrorist attacks.
The changes passed by Parliament on May 25 include allowing the police to make pre-emptive arrests and hold terror suspects longer for investigations, having the military support the police in counter-terrorism at home, and making it an offence to join foreign militant groups such as ISIS.
General Tito said there were lessons learnt from the recent spate of terror-related incidents. "First, that such a beautiful city like Surabaya can become a target of terrorism," he said. "Second, terrorism these days involves families, including mothers and their children."
Separately, the National Counter-terrorism Agency (BNPT) on Thursday signed a memorandum of understanding with the Ministry of Law and Human Rights to share information on foreign terrorist fighters (FTFs) and terrorist inmates currently held in Indonesia's prisons.
FTFs typically refer to Indonesians who have joined groups such as ISIS overseas.
Latest figures indicate that at least 1,489 Indonesian citizens have joined ISIS, or have left home trying to link up with the extremist group in Syria, sometimes taking their families with them. Of these, more than 600 have returned home on their own or were deported.
BNPT chief Suhardi Alius said the agency currently has no foolproof way of monitoring these returnees, or other foreign fighters who may enter Indonesia to mount terror attacks, and hopes to work with the ministry to ring-fence these militants, reported state news agency Antara on Friday.
He added: "The flow of Indonesians and foreigners must be monitored by the ministry's Directorate-General of Immigration."