By Steve Kingstone BBC correspondent in Mato Grosso do Sul

The Indians have vowed to fight to the death for the farms

Around 3,000 indigenous people invaded 14 farms in the state of Mato Grosso do Sul before Christmas.

Indian families have camped inside farm buildings and on the surrounding land.

They say the land is ancestrally theirs and have refused to leave, but the farmers have threatened to evict the Indians by force.

Negotiations

I have been allowed on to the largest of the farms occupied by Indians.

There is much chanting and dancing going on.

They are dancing around a wooden sign we would normally hang over the main entrance of a farm.

Some have pitched tents next to the main satellite dish of the farmhouse.

There is graffiti on the walls saying "evi catu" - a phrase that keeps reappearing. It means "the land that can be".

That is a reference to the fact that these people say their ancestors lived here, long before the land was sold to Brazilian farmers in the 1930s.

Indian leaders are currently negotiating here with local prosecutors, with a view to settling this dispute.

But they say that if the farmers return to reclaim the land by force, they will fight to the death defending it.