Singapore disclosed Wednesday it arrested 27 Bangladeshi construction workers late last year for supporting “the armed jihad ideology” of militants like the Islamic State group, and deported 26 of them.

The workers were being groomed to return to their home country to wage holy war and had studied booklets on assassination techniques, the Ministry of Home Affairs said in a statement.

“They were plotting nefarious activities in Bangladesh and other countries, and not in Singapore. But they were still a serious threat to us,” Prime Minister Lee Hsien Loong said in a Facebook post late Wednesday.

… Kumar Ramakrishna, a counter-terrorism analyst at Singapore’s S. Rajaratnam School of International Studies, said the arrests would likely be “disconcerting” to the public as foreign workers have become part of Singapore’s social landscape.

“It drives home the point that terrorists can be amongst us and not far away,” he told AFP.