Singapore authorities have intercepted and deported four Indonesian would be jihadi fighters travelling to Syria via the island state.
The suspects, including a 15-year-old boy, were the followers of convicted terrorist Aman Abdurrahman, who is believed to have ordered the January 14 terror attack in Jakarta, police said.
"These four men are from the Batam orphans foundation. They are followers of Aman Abdurrahman," Indonesia's National Police chief Gen. Badrodin Haiti said, according to Jakarta Post.
Aman was sentenced to nine years in prison for involvement in military training in Aceh and is serving his term at the is serving time in the high-security Nusakambangan prison island in Cilacap, Central Java.
The four, named as Muhammad Mufid Murtadho, Untung Sugema Mardjuk, Mukhlis Koifur Rofiq and Risno, were arrested at the Woodlands checkpoint as they were trying to enter the country from Johor, the Straits Times reported.
The suspected militants were handed over to Indonesian police on Batam island.
Two of the arrested men are related and all of them had made multiple trips to Mecca for pilgrimage, police said. One of them had been to Syria where he spent several weeks.
There were strong indications that the arrested men were supporters of the Islamic State terrorist group, National Police spokesman Insp.Gen Anton Charliyan said.
Indonesia has said in recent weeks it busted several terror cells and arrested scores of Islamic hardliners.
Draft terrorism law
The latest arrests come after the government submitted to parliament a raft of new laws tightening the anti-terror operations.
The draft terrorism law submitted to the parliament makes arrests and detentions easier by broadening the definition of terrorism.
"The new definition of terrorism includes the possession, distribution and trade of any weapons ... or potential material that can be used as weapons for terrorism acts," an unnamed source told Reuters last week.
The law also allows police to arrest those who recruit members for militant groups or offer other forms of help to the outfits. Police can also use electronic communications, intelligence reports and financial transactions as evidence in court against suspects.