Wildlife authorities are using aerial drones to oversee a sprawling natural game park in Assam to protect the one-horned rhinoceros from armed poachers.

Security officers conducted flights of the unmanned aircraft over the Kaziranga National Park on Monday and will fly drones at regular intervals to prevent rampant poaching in the park.

The drones are equipped with cameras and will be monitored by security guards, who find it difficult to guard the whole 480-square km reserve.

“Regular operations of the unmanned aerial vehicles will begin once we get the nod of the Defence Ministry,” said Rokybul Hussain, the state’s forest and environment minister.

The drones will also be useful during the annual monsoon season when large areas in the Kaziranga reserve are flooded by the mighty Brahmaputra River and three other rivers that flow through the game park, park officials said.

Poachers armed with automatic rifles killed 22 rhinos last year, but have killed 16 rhinos already this year.

Rhino horn is in great demand in China and Southeast Asia where it is believed to have medicinal properties.

A rhino census conducted in Kaziranga reserve two weeks ago put their number at 2,329, up from 2,290 in 2012.

In recent weeks, wildlife authorities in Assam have deployed 300 armed guards to protect the rhinos in Kaziranga but they have been no match for organised gangs of poachers who have been managing to strike at the rhinos with increasing regularity.

“What worries us is the use of automatic weapons like Kalashnikovs by the poachers,” said Assam police chief Jayanta Narayan Choudhury.