The cellphone tower was being reportedly used by guerrillas for communication in north Kashmir's Sopore town, a top intelligence source said.
The source told IANS that technical staff of a mobile phone company had gone to refill diesel in the power generator at one of the company's towers in Sopore on Thursday evening.
"The team discovered a device at the transmitting tower which was not installed by the company. They climbed up the tower and removed the device. The device was a high frequency transmitter installed unauthorisedly by militants," the intelligence source said.
"Later, some unidentified people barged into the local office of the company and thrashed the staff asking them to return the device immediately or be prepared to face the consequences.
"These unidentified people also thrashed the staff of another cell phone company in the town which indicates the unauthorised device removed from one tower may not be the only one being used for communication by the militants."
The development has been described by security agencies here as serious because mobile phone towers are present throughout the length and breadth of Jammu and Kashmir.
If the misuse of these towers for militant activities in Sopore has not been a one-off incident, the security forces could be facing a major challenge in the coming days to break the communication network of guerrillas, sources said.
Sources said the militants normally carry low-range hand-held transmitters which are used for short-range local communication.
"For long-range communication, they need a high-powered long-range signal transmitting and receiving device. Even if they have such devices, these are not effective unless installed at a suitable height.
"The height of the towers built by the mobile cellphone companies to transmit mobilephone signals is ideal for long-range communication of any kind. The other alternative is to have satellite phones for such long-range communication," the source said.
The intelligence source said the misuse of these towers could enable the guerrillas communicate across the Line of Control (LoC) and the international border in Jammu and Kashmir in addition to their having better communication in the hinterland.