JAKARTA - The woman arrested by Indonesian anti-terror police in Bekasi, West Java on Saturday with a home-made bomb, had planned to strike at Istana Merdeka in Jakarta on Sunday (Dec 11).
The police said the female suspect, identified only with the initials DYN, was given the 3kg "rice-cooker bomb" by two accomplices to mount a suicide-bombing in the capital.
Jakarta police spokesman Awi Setiyono told reporters on Sunday that DYN, whom he referred to as a "pengantin", had sent a farewell letter to her family. "The police managed to intercept her letter to her parents," said Colonel Awi.
Pengantin means bride in Bahasa Indonesia, but is widely used among Islamic militants to describe martyrs. DYN, who is 27, is believed to be from Cirebon in West Java.
Colonel Awi added that the bomb was brought to DYN in Bekasi from Solo, in Central Java, by two male suspects, MNS and AS.
Both men were nabbed by the police counter-terrorism unit, Detachment 88 (Densus 88) along an overpass in Kalimalang, an area in East Jakarta, on Saturday at 3.40pm, 10 minutes before another operation was carried out at a lodging house in Bekasi, to arrest DYN.
The bomb was seized by Densus 88 in a room in the lodging house located in Bintara Jaya, a residential area in Bekasi, located about an hour's drive from Jakarta - and where the three suspects have been staying for the last week or so.
The improvised-explosive-device, or IED in military speak, however, was built by a fourth suspect arrested by police in Karanganyar regency in Central Java at about 6pm on Saturday. Two other suspects linked to the foiled plot remains on the run.
"This is a new (terrorist) cell and they had learned to make bombs from Bahrun Naim using the Telegram messaging (smartphone) application," said Colonel Awi, citing initial investigations.
Bahrun Naim, is an Indonesian militant who is in the Middle East fighting alongside the Islamic State in Syria and Iraq (ISIS).
Istana Merdeka is a building within the Presidential Palace compound in Jakarta, where President Joko Widodo receives visiting heads of states as well as holds meetings with his Cabinet.
Jakarta police spokesman Raden Prabowo Argo Yuwono said earlier that the suspects were planning to detonate the "rice-cooker bomb" during Sunday's Changing of the Guards ceremony which takes place in front of Istana Merdeka.
According to The Jakarta Post, the public has been allowed to observe the ceremony on every second Sunday of the month. It starts at 8am local time (9am in Singapore) and usually attracts a sizable crowd.
Densus 88 on Saturday foiled the terror plot after arresting the four suspects and seizing the bomb which contained explosives more powerful than military-grade TNT. "That bomb could destroy anything within a radius of 300m," said Mr Argo.
The four suspects are currently being held for questioning but the police believed they are tied to recent terror incidents in Indonesia, including the July attack on a police outpost in Solo. Bahrun Naim is believed to have ordered the Solo attack from Syria.
The four suspects are also said to be followers of the Jamaah Anshar Daulah Khilafah Nusantara (JAKDN), which was formed sometime in March 2015, and said to have pledged its allegiance to ISIS.
The JAKDN is mainly made up of different members of the old Jemaah Islamiyah (JI) terrorist network, as well as other domestic groups Jamaah Ansharut Tauhid (JAT), Mujaheedin Indonesia Timur (MIT), Mujaheedin Indonesia Barat and Tim Hisbah, according to the International Centre for Political Violence and Terrorism Research.
Analysts have said members of the group or its splinter cells, many based in Central or West Java, are known to have procured or made bombs meant for attacks in Indonesia.
Last month, police discovered a terrorist cell in West Java, capable of assembling bombs and acquiring military-grade explosives and foreign funding. They were planning to attack Parliament building, police headquarters, local television stations, a Buddhist temple and the Myanmar embassy in Jakarta. The Straits Times understands that the Myanmar mission was targeted because of Naypyitaw's alleged oppression of the Rohingya Muslim minority.
The emergence of the group, which police said had plans to strike during the December holiday season, is an escalation of the terror threat in South-east Asia, analysts have said.
It is also likely that they are linked to the latest cell arrested on Saturday, as they have the same modus operandi, said the source, noting that the two groups were planning to strike at similar targets in the capital.
So far, four members of the group have been arrested and their plot foiled. They are Rio Priatna Wibawa, Saiful Bahri, Bahrain Agam and Hendra Rizki. The police said then that they are followers of Jemaah Ansharut Daulah (JAD), another offshoot of JI and by default also loyal to ISIS.
JAD is purportedly led by Aman Abdurrahman - a jailed ideologue who managed to order his followers from prison to attack Jakarta on Jan 14. The perpetrators of the hit were killed during a siege, but at least 17 others have been charged with supporting the attack.