Jakarta, Indonesia (CNN) A militant who police accuse of plotting Thursday's deadly terror attack in Jakarta instructed his cells in Indonesia to launch the attack, according to Jakarta Police Chief Tito Karnavian.

Karnavian spoke to CNN one day after the violence erupted midday, killing at least two, wounding 24 and raising alarm about terrorism in the world's most populous Muslim country.

"We have been informed by our intelligence that an individual named Bahrun Naim, based on the communications ... instructed his cells in Indonesia to mount an attack in Indonesia," Karnavian said.

Naim, who police believe is living in Syria, was apprehended by Indonesian authorities in 2010 for illegal possession of ammunition and was brought to justice, the police chief said. Naim was sentenced to at least 2½ years in prison.

The militant then left Indonesia, and is in Raqqa, "as part of the high ranks of ISIS," Karnavian said.

"He created cells or a branch of ISIS named Katibah al Nusantara. His vision is to join, to unite all ISIS supporting elements in Southeast Asia, including Indonesia, Malaysia and the Philippines," the chief said.

Police spokesman Anton Charliyan had said earlier that Naim is in Syria but sent money back home to Indonesia to finance the attack.

Promoting extremism

A blog containing ISIS teachings likely belongs to Naim, according to an Indonesian anti-terror source.

The blog contains posts written in the Bahasa Indonesia language on how to conduct terror attacks, lessons learned from the Paris attacks, how to avoid intelligence surveillance, how to make homemade pistols and how to conduct guerrilla warfare in cities, among others.

Authorities in Indonesia have been monitoring the blog for two years, the anti-terror source said. He added it's "highly possible" the blog is run by Naim himself or by people posting on his behalf.

Karnavian said the difference between ISIS and terror groups formerly active in Indonesia, such as Jemaah Islamiyah and al Qaeda, is that the former is more dangerous because its ideology allows it to kill Muslims in a way that previous groups did not.

Eerie quiet

As the sun broke the day after the attack, corrugated iron covered the shattered windows of the Starbucks that had been the scene of so much destruction. Wreaths and tributes, expressing condolences to the victims and defiance against those who attacked, were stacked against the nearby police outpost.

Many bear the slogan #KamiTidakTakut , which translates to "We are not afraid," to express pride and conviction to stand up, rather than bow down, to terrorism.

Indonesians lay floral condolence messages next to the police traffic booth attacked by suspected ISIS militants Thursday. A suicide bomber launched the coordinated attack in Jakarta by self-detonating at a Starbucks across the street. 2 civilians were killed and at least 19 wounded. Indonesian police say 5 attackers died in the assault, the most brazen, deadly jihadist attack this city has seen in 6 years #Jakarta #indonesia #isis #KamiTidakTakut A photo posted by Ivan Watson (@ivancnn) on Jan 14, 2016 at 1:53pm PST

The small number of people laying tributes outside the coffee shop and police outpost told CNN they had rarely seen the bustling, 24-hour street so quiet.

Boni Marlen, a 22-year-old studying law, rode up to the scene on a mountain bike late Thursday night and shook his head.

"I want to be near the people who died to pray for them," he said, repeating the slogan, "we're not afraid." He said the extremists counted as only a small group. "We must fight them."

Many went on Facebook and Twitter to express their pride and conviction to stand up, rather than bow down, to terrorism.

We are Indonesians & we never affraid to terrorist.We always fight anything that wanna take us down. #KamiTidakTakut pic.twitter.com/ZZTuKwLMBB — Frandy W S Sahureka (@frandysahureka) January 14, 2016

"We are Indonesians & we never affraid to (sic) terrorist," one man wrote. "We always fight anything that wanna take us down."

This sentiment was echoed by President Joko Widodo.

"We should not be afraid and defeated by acts of terror like this," he said.

Chaos on a busy street

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It began around 10:55 a.m. Thursday (10:55 p.m. ET Wednesday) with a suicide explosion near a Starbucks on Thamrin Street, an entertainment and shopping district with various Western chain restaurants and stores.

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That set in motion two militants outside the coffee shop who seized two foreigners, dragged them into a parking lot and shot them, said Charliyan, the Jakarta police spokesman. They also opened fire at people on the street.

Heavily armed police soon swarmed the scene, firing on the militants and looking for other attackers.

The attackers responded by firing back and tossing two grenades at the officers, according to Charliyan. Minutes later, two more rode a motorcycle toward a nearby police post and blew themselves up.

First major attack in Jakarta since 2009

CNN security analyst Bob Baer likened the Jakarta attack to the November 13 Paris massacre in which terrorists linked to ISIS struck several locations at the same time.

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Yet the number of dead was nowhere near the toll of 130 in France, with Clarke Jones, a counterterrorism expert at Australian National University, calling it "fairly amateurish ... with hand grenades and firearms."

Photos: Deadly explosions, gunfight in Jakarta Employees inspect the damage on January 15, 2016 at the Starbucks cafe where deadly attacks occurred the day before in central Jakarta, Indonesia. ISIS claimed responsibility for the attack in an official statement posted online. Hide Caption 1 of 18 Photos: Deadly explosions, gunfight in Jakarta Students light candles to express solidarity for those affected by the deadly attack in Jakarta during a vigil on January 14 in Surabaya, East Java, Indonesia. Hide Caption 2 of 18 Photos: Deadly explosions, gunfight in Jakarta A bouquet of flowers is placed in front of an explosion site on January 14 in Jakarta. Hide Caption 3 of 18 Photos: Deadly explosions, gunfight in Jakarta A policeman stands guard in front of a blast site in central Jakarta after a series of explosions rocked the heart of the Indonesian capital on Thursday, January 14. Hide Caption 4 of 18 Photos: Deadly explosions, gunfight in Jakarta Police and ambulances arrive in front of the Sarinah shopping center, next to a police station targeted by the attacks, on January 14. Hide Caption 5 of 18 Photos: Deadly explosions, gunfight in Jakarta Armed police officers keep watch outside a damaged Starbucks cafe after an attack in Jakarta on January 14. Hide Caption 6 of 18 Photos: Deadly explosions, gunfight in Jakarta Police officers stand guard outside a Starbucks cafe in Jakarta's bustling shopping area, near the site of an explosion, on January 14. Hide Caption 7 of 18 Photos: Deadly explosions, gunfight in Jakarta Police officers are deployed near the site where a series of blasts rocked downtown Jakarta on January 14. Hide Caption 8 of 18 Photos: Deadly explosions, gunfight in Jakarta Indonesian police take position and aim their weapons as they pursue suspects outside a cafe after explosions went off in Jakarta on January 14. Hide Caption 9 of 18 Photos: Deadly explosions, gunfight in Jakarta Smoke billows from an explosion in downtown Jakarta on January 14. Hide Caption 10 of 18 Photos: Deadly explosions, gunfight in Jakarta Plainclothes police officers aim their guns at suspects outside a cafe after a series of blasts hit the center of Jakarta on January 14. Hide Caption 11 of 18 Photos: Deadly explosions, gunfight in Jakarta Smoke rises following a series of blasts outside a shopping center in Jakarta on January 14. Hide Caption 12 of 18 Photos: Deadly explosions, gunfight in Jakarta Indonesian police take position behind a vehicle as they pursue suspects after a series of blasts hit the center of Jakarta on January 14. Hide Caption 13 of 18 Photos: Deadly explosions, gunfight in Jakarta A policeman fires his handgun towards suspects outside a cafe on January 14. Hide Caption 14 of 18 Photos: Deadly explosions, gunfight in Jakarta Hide Caption 15 of 18 Photos: Deadly explosions, gunfight in Jakarta A body lies in the middle of the street near a damaged police post on January 14. Hide Caption 16 of 18 Photos: Deadly explosions, gunfight in Jakarta Police hide behind vehicles during an exchange of gunfire with suspects hiding near a Starbucks cafe when another blast took place in Jakarta on January 14. Hide Caption 17 of 18 Photos: Deadly explosions, gunfight in Jakarta Police appear to chase suspects thought to be hiding at a cafe on January 14. Hide Caption 18 of 18

"It's concerning (to have) yet one more day and another attack in another part of the world," Sajjan Gohel of the Asia-Pacific Foundation think tank told CNN. "And one fears that this is potentially becoming the new normal where ISIS affiliates carry out attacks independently from the leadership based in Syria."

Dutch national among the wounded

The blasts and gunshots stopped by Thursday afternoon. And by nighttime, authorities were no longer hunting for attackers -- though they are looking for those who helped them in plotting, financing and getting weaponry, Charliyan said.

By then, police had already counted five assailants dead at the scene. They also discovered several unexploded munitions, some of them high-grade explosives, at the scene, the police spokesman said.

One foreign national and one Indonesian make up the dead, authorities said. Charliyan said 24 people, including at least one more foreigner, were wounded.

The ISIS statement claimed "nearly 15 Crusader foreigners" died in the attack, though there are no official reports indicating that's true. The group said that its fighters "targeted a gathering of nationals of the Crusader alliance" -- suggesting they were going after not Indonesians but citizens of other countries, many of whom have a role in the far-reaching campaign against ISIS.

It added that the operation was intended to "teach the citizens of the Crusader alliance that it does not protect them" or guarantee them "safety in the Muslim lands."

Angele Samura, the security adviser for the Netherlands Embassy in Jakarta, said a Dutch national underwent surgery after being "severely injured." It's not known if this is the same Dutch citizen and U.N. Environment Programme worker who that agency reported was hurt.

Worries about ISIS fighters returning home

In recent weeks, Indonesian police have been on high alert, while military operations focus on hitting the East Indonesian Mujahadeen, helmed by Indonesia's most-wanted terrorist, Santoso, who has pledged support for ISIS.

One major worry is that Indonesians fighting in Syria and Iraq will return home, having gained training and combat experience.