Indonesian bombmaker Dodi Suridi, 23, was sentenced to 10 years in jail by a district court yesterday, for helping to make the explosives used during a terrorist attack in Jakarta in January.
A second suspect, Ali Hamka, 47, was jailed for four years, after he was found guilty of trying to acquire firearms for the same strike.
The two men are the first among a group of at least 17 suspects to be convicted for the brazen attack on the Indonesian capital, which the Islamic State in Iraq and Syria (ISIS) had claimed responsibility for.
The Jan 14 attack was mounted by the "Jakarta Four" of Sunakim alias Afif, Muhammad Ali, Dian Juni Kurniadi and Ahmad Muhazin, who were armed with pistols, home- made bombs and grenades.
Neither Dodi nor Ali Hamka was at the scene of the siege, which left eight people, including the four perpetrators, dead.
But prosecutors said evidence, including remnants of improvised explosive devices (IEDs), indicated the two had critical roles in the preparations for the hit.
The court heard that IED debris such as part of a gas canister used as a bomb casing, found near the police post where the attack took place, was traced to Dodi.
Details in court documents show that Dodi was told by Sunakim last November in Tegal, Central Java, that bombs were needed for an attack on either the Russian or Iranian embassy in the city.
Ali Hamka, on the other hand, had tried but failed to supply firearms to the Jakarta Four, said District Judge Maha Nikmah.
The judge, however, found that Ali Hamka had actively promoted violent ideology, even sending his son to Poso, Central Sulawesi, to join the East Indonesia Mujahideen. The militant group was led by Indonesia's most wanted terrorist, Santoso, who was killed by security forces in July.
Another presiding judge, Judge Achmad Fauzi, said during sentencing that the case against the defendants had been "convincingly proven" by the prosecution.
"I accept (the jail sentence), this is the risk of being a terrorist, Allah is Great," Dodi said, after the judge read out his punishment.
As with many militants who go by noms de guerre, Dodi uses the aliases Ibnu Arsad, Yayan and Dodi Dabiq, while Ali Hamka is also known as Abu Ibrahim, Abu Musa and Abu Isa.
Ali Hamka is also a former leader of a defunct Jemaah Islamiah cell in Indramayu, a West Java regency.
Both belong to a terror cell in Cirebon, also in West Java, and had pledged allegiance to ISIS last year.
They were arrested in their hometown on Jan 15 - the day after the Jakarta attack.
Sources said they were already under surveillance by the elite Detachment 88 counter-terrorism unit.
The Straits Times understands that the Cirebon cell was formed by Bahrumsyah, an Indonesian militant believed to be in the Middle East fighting alongside ISIS forces.
Some analysts and confidential sources have said that contrary to previous reports, Bahrumsyah may have ordered the strike in Jakarta.
But National Police chief Tito Karnavian had said previously that the hit was directed by Bahrun Naim, another Indonesian militant who has joined ISIS in Raqqa, Syria.
The National Counterterrorism Agency on Wednesday said there have been 69 terror attacks in Indonesia since 1999, with many of the recent cases committed by home- grown militants loyal to ISIS.
Yesterday, an unemployed man attacked two officers at a police post in Tangerang, which is about an hour's drive from Jakarta.
The suspect, 21-year-old Sultan Azianzah, was armed with knives.
He was shot by a third police officer and died en route to hospital, said a police spokesman. Two knives and two items resembling pipe-bombs were seized from the scene as part of investigations.
ISIS has laid claim to the latest attack on the police officers.