JAKARTA - Indonesia's president ordered police on Wednesday to step up surveillance after at least a dozen people went missing and are believed to have joined a little known group that authorities have described as radical and dangerous.
The order from President Joko Widodo came during a period of heightened concern about the danger of Islamist militants and a crackdown by counter-terrorism police on people with suspected links to Islamic State.
The more than a dozen men and woman were reported missing by their families and there were strong indications they had joined a group known as Gafatar, authorities have said.
"This has the potential to disturb public security," Cabinet Secretary Pramono Anung said in an online statement. "We have been asked by President Joko Widodo to monitor this."
Anung said little was known about the group but the religious affairs ministry had been asked to help the police in investigating.
Police last month rounded up several men across Java island who were found with bomb-making materials, a suicide-bomb vest, and books on waging jihad.
The men were believed to have been targeting Christmas and New Year's Eve celebrations in the capital, Jakarta, and other cities.