On Friday, troops took over most of El Rodeo jail in Guatire, after a riot between rival gangs of prisoners a week ago left some 20 people dead.

But a stand-off continues in one prison wing, after attempts to negotiate with a group of armed inmates failed.

The interior minister said some 50 prisoners were refusing to disarm.

In the meantime, the authorities have sought to deal with the prisoners from the part of El Rodeo they already control.

In the early morning of Sunday, they began transferring some 2,500 inmates by bus to a number of other prisons in the country.

They planned to move the remaining 1,000 inmates later in the day.

Officials say the measure is temporary, designed to protect the fundamental rights of the prisoners.

'Short circuit' fire

Many of the inmates' relatives, however, remain highly anxious about a situation that is still very volatile.

Two members of the security forces and at least one prisoner were killed in clashes inside the jail when the security operation started on Friday.

Hundreds of relatives have gathered outside the jail, where they have clashed with security forces in recent days.

Some of them watched with great alarm as a fire broke out in part of the prison before dawn on Sunday.

The Venezuelan authorities denied that they had started the fire deliberately.

A senior government official, Nestor Reverol, said the blaze - which has since been put out - had been caused by an electrical short circuit and that no-one had been hurt.

Waiting game

Attempts to end the stand-off inside part of El Rodeo have so far failed.

On Saturday, Interior Minister Tareck el-Aissimi said the leaders of a group of inmates - whom he called "hostile" and "negative" - had been using their weapons to exert control over more than 1,000 fellow inmates in that area of the jail.

Mr Aissami told the state television channel, VTV, that the leaders were demanding that government troops - who number some 4,000 - pull out of the jail.

And he said the men would not permit a search of the part of the prison they controlled.

The authorities have been trying to implement a crackdown on guns within the jail, and have so far confiscated a number of firearms and a quantity of drugs.

But Mr Aissami said he was prepared to play a waiting game.

"We'll last out for as long as it takes," he said.

"Time is not on their side. We're on our guard, waiting for them to hand over their weapons."