Singapore has detained eight Bangladeshi workers on suspicion of planning attacks linked to the Islamic State group in their home country, authorities said Tuesday.

The Ministry of Home Affairs said the eight construction and marine workers were detained last month for allegedly being members of the group Islamic State in Bangladesh and are currently under investigation.

It said they were arrested under the city-state's Internal Security Act, which allows for detention without trial in cases where public safety is threatened.

The ministry said the suspects had intended to join the Islamic State group in Iraq and Syria as foreign fighters but discovered that it would be difficult to make their way there. The group then focused on returning to Bangladesh, where at least two more members are believed to be based, it said.

They made plans to "overthrow the democratically elected government through the use of force, establish an Islamic State in Bangladesh and bring it under ISIS' self-declared caliphate," it added, using another acronym for the Islamic State group.

"The group had also raised monies to purchase firearms to carry out their planned terror attacks in Bangladesh. The money has since been seized," it said.

The ministry said an investigation revealed documents containing possible targets in Bangladesh and a list of government and military officials. It said the group's suspected leader, Rahman Mizanur, possessed guides on making weapons and bombs and also radical material from the Islamic State group and al-Qaida that he used to recruit the others.

Five other Bangladeshi workers were investigated under the Internal Security Act for alleged links to the Singapore-recruited group and were subsequently deported for supporting the use of violence for a religious cause and possession of jihadi-related materials, the ministry said.

"Rahman Mizanur has said he would carry out an attack anywhere if he was instructed by ISIS to do so, though there are no specific indications that Singapore had as yet been selected as a target. Several of those detained may be liable for prosecution for terrorism financing," the ministry said in a statement.

In January, Singapore said it had arrested and deported 26 Bangladeshi construction workers for forming a religious study group that spread the ideology of al-Qaida and the Islamic State group.