Two Bangladeshi nationals, suspected to have links with the Garo National Liberation Army (GNLA), were arrested along with an Indian from a village in West Khasi Hills, the police said in Shillong on Saturday.
The two, Himanshu J Sangma and Aloka Marak, hailed from Mymensingh district in Bangladesh, the sources said.
Samson J Sangma, from whose house they were arrested on Friday, was also taken into custody.
Police recovered some documents from their possession, which, the sources said, could provide leads to their involvement with the GNLA.