Colombia's civil war is 38 years old

Government troops backed by helicopter gunships intervened after the FARC appeared to get the upperhand.

Correspondents say their prompt arrival contrasts sharply with the situation in the neighbouring province of Choco earlier in May when government troops took five days to reach a village where 119 civilians had been killed in a church by a single FARC mortar bomb.

Campamento, a remote town about 512 kilometres (318 miles) northwest of the capital Bogota, is only 70 km from Bojaya, the scene of the mortar attack.

Campamento's parish priest, Ovidio Castro, said helicopter gunships were bombarding the area and the fighting was continuing.

Most of the dead from the fighting appear to be from among either the FARC or the AUC, the Colombian authorities say.

The provincial governor, Eugenio Prieto, has urged international humanitarian agencies to help out as Antioquia's resources are overstretched.

FARC stronghold

The BBC's Jeremy McDermott says that FARC has been the undisputed masters of Campamento since destroying the police station there in 1999.

When the FARC beat off the AUC attack, wounded paramilitaries fled into the town, hiding their weapons and removing their uniforms.

But they were pursued by FARC guerrillas, who dragged them into the streets and killed them.

Both groups are outlawed in Colombia but control much of the territory since the civil war loosened the government's hold.

Army impotent

Since the breakdown of peace talks between the government and the FARC in February, the guerrillas have escalated their attacks across the country, particularly against the AUC.

Uribe plans to boost spending on the army and police

And the army has been stretched to breaking point, all too often becoming an impotent observer as the two illegal forces slug it out for territorial control, our correspondent says.

Security is dominating the presidential election, due to be held 26 May.

The favourite, Alvaro Uribe, has climbed to the top of the polls with talk of instituting authoritative government.

But with the illegal armies growing stronger all the time, and the state unable to react to, let alone contain the violence, nobody is quite sure how he plans to achieve such a miracle, our correspondent says.