The National Counterterrorism Agency ( BNPT ) is hunting down scores of Indonesians at home and abroad who have joined the Islamic State of Iraq and Syria (ISIS), the agency's chief says.

The Indonesian government banned ISIS and vowed to punish citizens who break national laws by signing up to fight for ISIS. Late last month, the BNPT announced that in co-ordination with the Foreign Affairs Ministry , it was sending a team to the Middle East to gather intelligence about Indonesians taking up arms in that region for ISIS.

BNPT head Ansyaad Mbai warned the numbers of Indonesians joining ISIS may be growing.

"Our current estimation is about 100 Indonesian citizens. The number could be more," he told Khabar Southeast Asia. "We do not have an exact number. Therefore, the [purpose for the] team's departure will be to assess these numbers."

"If we know how most of these people are entering Iraq or Syria through third countries such as Turkey, Qatar, and Egypt, once we have evidence of their involvement, then we can charge them under the Anti-Terrorism Law," Ansyaad said.

Many of these Indonesian ISIS recruits come from terrorist hotbeds such as Tangerang, Banten, Bekasi in West Java and Poso in Central Sulawesi, the counter-terrorism chief added.

Co-ordinating Political, Legal and Security Affairs Minister Djoko Suyanto said the government would continue to counter ISIS's domestic recruitment efforts .

"We should stop any community-based organisation that represents ISIS's interests directly or indirectly. We will also need to co-ordinate with other countries to ensure legal immigration processes. Additionally, we will also need to anticipate any possible recruitment through social media ," Djoko told Khabar.

"Their place is not here"

In Bekasi, residents are speaking out against ISIS.

All elements of society are responsible for uniting as a force to ward off the ISIS threat, local cleric Muhammad Iqbal Bahari said.

"They are threatening all aspects in our society. They are threatening Islam as a religion, putting our kids in danger and exposing them to violence," he told Khabar, adding the terrorist organization should not be allowed to exist in Indonesia.

"Their place is not here," Iqbal continued. "Indonesian Muslims have co-existed with other religions for decades, and will continue to do so."

Riswanti Mahreni, a 24-year-old who lives in the Bekasi neighbourhood of Duren Jaya, accused ISIS of disseminating misleading ideology .

Neighbourhood residents came together to put up banners proclaiming their opposition to ISIS's evil ways, she said. "ISIS encourages violence not only against Islam but also against humanity."