Indonesian police said they have arrested two more suspected militants including a member of China's ethnic Uighur minority who was allegedly preparing to be a suicide bomber.
National Police spokesman Maj. Gen. Anton Charliyan says the suspects were captured in two separate places Wednesday in Bekasi, a West Java town bordering with eastern Jakarta.
The arrests of Arif Hidayatullah, alias Abu Mush'ab, and Alli, the Uighur who used a fake identity card, came as security has been stepped up after officials described a credible threat of attacks, especially against minority Christians, during the year-end holidays.
The government has deployed 150,000 security personnel to safeguard churches, airports and other public places across this predominantly Muslim nation.
At the same time about 1,300 security personnel are hunting Indonesia's most wanted militant, Abu Wardah Santoso, who has pledged allegiance to the Islamic State group. The leader of the East Indonesia Mujahidin is hiding in Central Sulawesi.
More than 800 Indonesians are believed to have joined IS in Syria or Iraq.
"Learning from history, we have to be alert against terrorism,'' Charliyan said. "Threats from terrorists could not be ignored.''
Hidayatullah, an employee at a private auto company, was nabbed Wednesday morning while on way to his office. Evidence police said they confiscated a list of militants who are in prisons and others who are fighting with IS in Syria.
Police say he confessed he was ordered by Bahrunnaim, another militant who is now in Syria, to act as a coordinator or facilitator for Indonesians wanting to join IS.
Alli came to Jakarta two months ago and is known as a bomb maker.
Charliyan said police found homemade bombs in a car and confiscated explosive materials in their houses.
"We even discovered a vest prepared for the suicide bombing and a map of a government building they planned to attack,'' he added.
Top security officials have warned that they have received intensive intelligence about the possibility of radical attacks especially at airports and strategic areas.
National police chief Gen. Badrodin Haiti said "there are many possible threats and vulnerabilities, ranging from conventional crimes to terrorism and radicalism.''
Over the weekend authorities arrested nine suspected Muslim militants in Tasikmalaya, another West Java town, Central and East Java. Authorities alleged they planned to attack government officials and minority Shiite Muslims.