Violence erupts in southern Mexico

The area is also close to a Zapatista stronghold

By Peter Greste in Mexico City

There has been an outbreak of violence in Mexico between supporters of rival political groups in the troubled southern state of Chiapas.

Details are sketchy, but local police say four people have been killed and more than 20 injured in clashes between supporters of the Institutional Revolutionary Party (PRI) and their opponents.

The vast majority of the population of the Chiapas lives in poverty

They say the trouble erupted on Tuesday afternoon in the remote jungle hamlet of Pena Limonar, less than two days after local elections in which the party lost control of the state for the first time in seven decades.

The village is some six or eight hours by road from the nearest police station.

Trouble predicted

The authorities say it could take some time to reach the site and confirm the details.

At this stage, it is impossible to say why the two groups were fighting, although soon after the election results were announced, many political analysts predicted trouble.

They argued that local village strongmen, who rely on the PRI's patronage for power, would be reluctant to accept the result.

The area is also close to a stronghold of the Zapatista guerrillas who launched an uprising in support of greater indigenous rights six-and-a-half years ago.

But in the state's deeply complicated political landscape, there is no way of knowing exactly who was involved in the incident.

Analysts have warned though that clashes are likely if the result of Sunday's historic opposition election victory sinks in to those with plenty to lose.