GUWAHATI: The BSF has recently procured Israeli tethered drones and thermal imagers to check smuggling and illegal infiltration in Dhubri sector of Assam, where a major part of the India-Bangladesh border passes through a riverine stretch, making it difficult to erect fences.

The drones, equipped with day-night vision cameras, can fly up to a height of 150 metre to capture images on the ground, especially of isolated areas not visible to unaided human eye, Piyush Mordia, the Inspector General (IG) of BSF's Guwahati Frontier, said.

"They (drones) are like kites capturing aerial view images. The cable attached to the drone is remotely controlled from the ground to adjust its height and directions," Mordia told PTI on Tuesday.

The 61-km-long border in Dhubri area of western Assam, where the Brahmaputra enters Bangladesh, comprises vast chars (sand bars) and multiple river channels that make border patrolling a daunting task, especially during the monsoons.

"Cattle smuggling and drug trafficking activities are usually carried out at night. These newly employed drones will be able to send images of smugglers hiding in the vicinity of the border area during day time," the BSF IG explained.

Given the topography of Dhubri district, miscreants often take the underwater route to sneak into the country illegally, Mordia stated.

"The BSF has also engaged underwater thermal imagers - which are non-contact temperature measurement sensor devices - to detect movement of people, animals and smuggled goods.

"The tethered drones and imagers will work as deterrents for cross-border smugglers once they found out they were under surveillance," he maintained.

Declining to divulge the exact number of drones engaged in the sector, Mordia said the aerial device would restrict its movement and images to the Indian Territory.

"The district administration imposes prohibitory orders on border areas under Section 144 CrPC, barring gathering of more than five persons. The drones in these areas will help manage crowd, especially when protests are organized or our men are attacked," the senior BSF official added.

Assam shares 263-km border with Bangladesh, of which 119.1 km is riverine.

The Union Ministry of Home Affairs had decided to opt for a technological solution along the border, besides the presence of BSF personnel.

Last year, the information and technology wing of the BSF had undertaken a smart fencing project and completed it in record time with the technical support of various manufacturers and suppliers.

In March this year, Defence Minister Rajnath Singh as then Union Home Minister in NDA-I inaugurated project BOLD-QIT (Border Electronically Dominated QRT Interception Technique) under CIBMS (Comprehensive Integrated Border Management system) in Dhubri district.

The new project will equip the unfenced areas along the riverine border with sensors, enabling the troops to take prompt action against intrusion, Singh had said.