Four members of the Kuki Revolutionary Army (KRA), a militant outfit, were arrested on Friday on charges of extortion, kidnapping and opening fire at several places, police said.
"These four KRA cadres had ambushed two oil tankers in Kangpokpi district (of Manipur) on Tuesday. No weapons were recovered. However four handsets and nine SIM cards were recovered from them," Director General of Police L.M. Khaute said.
"We believe that the different SIM cards were used to make extortion calls and for other illegal activities. The matter is under investigation," he added.
Khaute said the KRA has a nexus with the Kuki National Front (H) and the Kangleipak Communist Party (Lalheiba). The police is expecting some more breakthroughs, he added.
Police said the KRA is a signatory to the suspension of operations with the government. The main ground rules say that they cannot move around with arms and indulge in violence. They should be confined to the designated camps.