Afghan security force members take part in a military operation against Islamic State (IS) in Achin district of eastern Nangarhar province, Afghanistan, Sept. 16, 2019. Photo:Xinhua

Singapore has detained three Indonesian maids without trial under tough security laws over allegations they donated funds to support the Islamic State (IS) group, authorities said. 

It is the latest case of allegedly radicalized foreign domestic helpers arrested in the city-state, and the government said it highlighted the continued appeal of the jihadists' "violent ideology."

The trio, who worked as maids for between six and 13 years in Singapore, became supporters of IS after viewing online material last year, including videos of bomb attacks and beheadings, the interior ministry said.

Anindia Afiyantari, 33, Retno Hernayani, 36, and 31-year-old Turmini became acquainted around the time they were radicalized and developed a network of foreign contacts online who shared their pro-IS ideology.

"The three of them actively galvanized support online for ISIS," said the ministry in a statement late Monday, using an alternative name for IS.

"They also donated funds to overseas-based entities for terrorism-related purposes, such as to support the activities of ISIS and JAD. Turmini believed that her donations would earn her a place in paradise."

Officials did not say how much they contributed.

JAD refers to Indonesian militant outfit Jamaah Ansharut Daulah, which has pledged allegiance to IS.

The women are being held under the city-state's Internal Security Act, which allows for detention without trial for up to two years.

IS lost the last scrap of its self-declared "caliphate" this year but remains influential. There are fears that foreign fighters returning from the Middle East could rejuvenate terror networks elsewhere, including in Southeast Asia.

Before the latest three cases, authorities had detected 16 radicalized foreign domestic workers since 2015, though none were found to have plans to carry out violent acts in Singapore. They were repatriated after investigations.