Police in southern France on Friday escorted veterinarians to a farm to slaughter a herd of cows suffering from a potentially deadly disease, French news agency AFP reported.

The order to kill the cows at the farm in a village in the Ariege area sparked protests in recent days. Farmers tried to protect more than 200 cows that had nodular dermatitis, commonly referred to as lumpy skin disease.

France is tightening rules to deal with outbreaks of the disease. The French government said the culling, vaccination campaigns and restrictions on cattle movement are necessary to contain the disease.

Officials said psychological support would be offered to the farmers affected. 

What happened at the protests?

Protesters had been demonstrating for two days outside the farm before the culling. Dozens of them had stayed after nightfall on Thursday to block the farm in the village of Les Bordes-sur-Arize.

Some farmers and supporters, who see the culling order as exaggerated and cruel, had earlier chopped down trees and set up barricades to prevent the veterinary staff from entering.

On Thursday night, security forces said they had used tear gas to disperse the protests, while demonstrators hurled stones, branches and other makeshift missiles as hay bales burnt in the background.

Interior Minister Laurent Nunez said four people were arrested in the clashes.

Local authorities said the brothers who owned the farm were in support of culling the herd as a precaution against the disease. But protesters dispute this narrative, with the head of the union leading the protest saying one of the two brothers was against the slaughter.

"They are tearing this family apart," said Pierre-Guillaume Mercadal, of the local Rural Confederation union.

Why is France culling cows?

Lumpy skin disease has been detected in France since June. French authorities say the outbreak is under control thanks to a mass vaccination program.

In Ariege, some 3,000 of the 33,000 cattle in the region have been vaccinated.

The disease, spread by insects, cannot be passed to humans, but it can be deadly for the cattle. The infected cows suffer from blisters and reduced milk production.

Some cases have been reported in Italy and Spain this year.

An outbreak in 2012 spread from the Middle East to Greece, Bulgaria and the Balkans, and was stopped by a vaccination program.

Edited by: Karl Sexton