GAUHATI, India (AP) — An official says poachers using AK-47 assault rifles to hunt rare, one-horned rhinos in India’s insurgency-wracked northeast may be tied to the region’s insurgent groups.

Assam state police chief Jayanta Narayan Choudhury says the use of AK-47s suggests the involvement of rebels or former insurgents trying to cash in on the huge demand for rhino horns in China and Southeast Asian nations.

Poaching has been rampant in and around Kaziranga National Park in Assam state, where 21 rhinos were killed last year. The poachers used AK-47s to kill nearly a half-dozen rhinos in the past month, Choudhury said Wednesday.

Rhino horn powder is coveted in some Asian countries as a medicine or an aphrodisiac, and its popularity has led to a rise in rhino poaching.