JOHANNESBURG (AP) — Thousands of white farmers have snarled traffic on some major roads in South Africa in what they call their Black Monday protest against the high rate of murders of farmers.

Convoys of hundreds of slow moving hundreds of trucks and cars brought traffic to a crawl on highways leading from farming areas to Cape Town, Pretoria and Johannesburg and white farmers and their supporters wore black in memory of those farmers killed on their properties. The protests have been peaceful and the South African police have accompanied the demonstrators.

The protests are backed by AfriForum, a lobby group which promotes the rights of South Africa's white minority, especially the Afrikaner population descended from Dutch settlers. AfriForum claims that 70 white farmers have been murdered in 341 attacks this year.