A record number of rhinos were poached in South Africa last year, the country’s department of environmental affairs announced Friday. The spike in poaching has reportedly been driven by Asian demand for their horns.

The department reported 1,004 rhinos were killed illegally in 2013, up sharply from 668 the year before and 448 in 2011. The majority of attacks have taken place in Kruger National Park—606—even with its park service using drones and helicopters to sniff out suspected poachers. So far this year, 37 have been poached—close to three per day. South Africa’s rhino population is estimated to hover around 20,000.

(MORE: Poachers, Not Big Game Hunters, Are the Real Threat to Endangered Rhinos)

The horns are smuggled out of South Africa to Asia, specifically Vietnam and China, where they are viewed as a status symbol and used in traditional medicine.

The World Wildlife Fund issued a statement Friday from Dr. Jo Shaw, rhino program manager for South Africa, calling on South Africa and Mozambique—where many horns leave the continent—to make arrests higher up the trafficking chain to deter future killings.

[Reuters]