The Colombian authorities say they will continue to forcibly remove indigenous protesters from farms, after a teenager was killed during an eviction.
Indigenous leaders said the 16-year-old had been killed when police opened fire with live ammunition.
The police have not commented on the incident. One of their officers was reportedly injured by a petrol bomb.
The protesters say the farm is land that was promised to them by as part of an agrarian reform programme.
Some 500 police officials and 10 armoured vehicles were mobilised to evict the Guambiano Indians from the Japio farm, in the south-western province of Cauca.
Indigenous leaders said 30 protesters were injured in the clashes, one of them seriously.
The protesters held a vigil for the dead 16-year-old
The 4,000-hectare (9,900-acre) farm is one of three occupied by 10,000 protesters in the mountainous Caloto area of the region since 12 October.
The Guambianos say these are ancestral lands illegally taken from them by settlers.
But the government insisted on Thursday that it would not negotiate with the group while it continued to occupy farms considered private property.
It said that this year the state had transferred 44,000 hectares (109,000 acres) of land confiscated from drugs traffickers to landless peasants.