JOHANNESBURG (Reuters) - South African police have intercepted 167 rhino horns believed to be destined for Southeast Asia, in one of the biggest such hauls ever in the country.

Two suspects, aged 57 and 61, were arrested with the horns on Saturday, police said on Sunday. They had been tipped off about the suspects’ vehicle.

“The value has not been determined -- it’s one of the biggest hauls in the country,” Brigadier Hangwani Mulaudzi, a police spokesman, said by text message on Monday. The case was still being investigated, he said.

Nearly 80 percent of the world’s rhinos live in South Africa. More than 1,000 rhinos were killed in the country each year from 2013 to 2017, according to conservation group Save the Rhino.

That figure fell below 1,000 in 2018, but it still means more than two rhinos were killed each day of the year. Two rhino species have fewer than 80 animals left in the wild.

Poaching is driven by demand for rhino horn - consisting mostly of keratin, found in human nails and hair - in countries like China and Vietnam, where it is used in traditional medicine and also increasingly seen as a symbol of success and wealth.

The government and international donors have poured money into anti-poaching measures and securing national parks.

The two suspects were due to appear at a magistrates court near Pretoria on Monday.