By Steve Kingstone BBC correspondent in Sao Paulo

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

Members of the Guarani and Kaiowa tribes invaded the farms, that they say are on ancestral land, last December.

A federal judge on 22 January sided with the farmers and ordered the indigenous people to leave the land.

But with legal proceedings making slow progress, the farmers have threatened to retake the land by force.

The Indians have occupied 14 farms in the state of Mato Grosso do Sul, near Brazil's border with Paraguay.

Uneasy peace

Armed with spears and bows and arrows, the Indians have promised to die fighting rather than give up the land.

The displaced farmers insist the properties were bought legally as far back as the 1930s.

Some have promised to return to their farms to evict the Indians by force using hired gunmen.

The local authorities are desperately seeking a negotiated settlement.

In the meantime, heavily armed police officers are patrolling the perimeter of the invaded area to preserve what is an uneasy peace.