JAKARTA - Soldiers who took out Santoso were lying in wait for days to strike, said Indonesian military (TNI) chief, General Gatot Nurmantyo.

"The team had to lay low for eight days in an area where they suspected Santoso would be, waiting for the right time to move in," said the general at the Coordinating Ministry for Political, Legal and Security Affairs on Tuesday (July 19).

"It was near the village of Santoso's wife."

General Gatot was speaking to reporters a day after the leader of the East Indonesia Mujahideen (MIT) militant group and Indonesia's most wanted terrorist was killed during a fire-fight with security forces in the jungles of Poso, Central Sulawesi on Monday.

The death of Santoso, who is also known as Abu Wardah, is regarded as a major victory for Indonesia's war on terror, said security experts.

It was also a result of teamwork and patient between the TNI, the Indonesian National Police as well as other military and intelligence units involved in Operation Tinombala, the kill-or-capture mission against Santoso and his men, said General Gatot.

He praised the troops on patrol in the Poso jungles, giving special mention to the team of soldiers who on Monday tracked down their number one target.

"The team that managed to shoot and kill Santoso left camp 13 days ago, there were nine of them on the team that reached the spot we suspected Santoso would be," he added.

Due to the rough terrain, the men took three days to trek a distance of 11km before arriving at the ambush point where they set up a hide and waited.

"They only moved at night to avoid being detected," said the general. "They were not the only team, there were others; but they were the fortunate ones that got Santoso."

The Army unit was also supported by surveillance drones operated by a team from the Indonesian Air Force, he added.

Some 3,500 troops from the TNI and the police had been deployed to comb the jungles and mountainous areas of Poso as part of one of largest manhunt for Santoso from January this year.

Santoso and his men from the MIT had pledged allegiance to Islamic State in Iraq and Syria (ISIS) in 2014 and were behind numerous attacks on police since 2012.

Before he was killed on Monday, there was increasing concern in Indonesia that Santoso and the MIT may grow into a force comparable with Islamist militant groups in the southern Philippines or separatists in southern Thailand.

He is said to have received funds from Islamic State in Iraq and Syria (ISIS) and was behind several threats issued last year, including a nine-minute video on social media sites that called for strikes on the Jakarta police headquarters and the presidential palace in December.

In March, the United States imposed a special terrorist designation on Santoso, blocking any US assets he might have, banning dealings with him by Americans and opening the way for American law-enforcement action against him.

The police said he was one of two MIT combatant who sustained fatal injuries after a skirmish with troops. Three others, possibly his wife, another woman and a third man, managed to escaped.

Coordinating Minister for Political, Legal and Security Affairs Luhut Pandjaitan on Tuesday (July 19) that even though Santoso has been killed, Indonesia security forces would continue their pursuit of the remaining members of his group in Poso.

"We will continue to pursue them, there are up to 19 others," he said, adding that troops on the ground will be reinforced to suppress the rest of their militants still at large.

tkchan@sph.com.sg