Ham radio operators working with the security forces to track down radio communications of underground GJM leaders have picked up "suspicious and coded signals" of the activists to other countries and states.
The security forces and intelligence agencies first got the clue that the GJM was using radio signals as a mode of communication when two radio sets were seized during the June 15 raid on the premises of some Gorkha Janamukti Morcha (GJM) leaders.
It was then that the police administration decided to deploy a group of Ham radio operators to track the radio communication of GJM activists.
The operators picked up the suspicious cross-border signals during the drill.
"Most of the coded signals and communications were in Nepali and Tibetan languages. After decoding the words, we came to know about some kind of consignment that is about to come. The rest is classified and we cannot disclose it," an official privy to information told PTI.
Ham or amateur radio operators are under the Ministry of communications and are licenced cardholders to conduct such communication under specific radio frequencies.
A team of ham radio operators is monitoring the radio signals round-the-clock and another team of language experts is helping the officials break the coded language, he said.
Radio communication among leaders of pro-Gorkhaland leaders and activists has increased by "leaps and bounds" after Internet services were suspended on June 18 and their phones are being tracked by the agencies, the official said.
Several top GJM leaders have gone into hiding after last week's violence in the hills.
According to official sources, the GJM has imparted radio communication training to its cadres and has also set up small temporary radio stations in various parts of the hills. It is through these radio stations that such signals are being sent and received.
"Some of the radio communications have pointed out that they were well prepared for a showdown and the violence in the hills is not just an incident which happened in the heat of the moment. It was pre-planned," said an official.
GJM General Secretary Roshan Giri, however, denied recovery of any kind of radio sets and called it a malicious campaign of the state government to defame the party.