Fernandez's arrest has aroused concern abroad

Carlos Fernandez, head of the Fedecamaras business organisation, faces treason charges for his part in organising a two-month strike against the leftist government.

President Chavez has called for Mr Fernandez and a fellow strike leader now in hiding to be given 20-year prison terms, accusing them of sabotaging the country's crucial oil industry.

I went to bed with a smile President Chavez, speaking after the arrest of Carlos Fernandez

The opposition has called for new demonstrations in the capital after thousands marched through Caracas on Thursday in protest at Mr Fernandez's arrest.

His fellow strike leader, Venezuelan Workers Confederation (CTV) leader Carlos Ortega, is in hiding, saying he will not allow himself to "become easy prey for the current administration".

"It is not possible to come out in public... not only because we might be arrested at any time, but because our physical safety would be compromised," Mr Ortega said in an interview quoted by Venezuelan radio.

'Criminals'

President Chavez has accused the strike leaders of sabotaging the oil industry, inciting civil disobedience and "trampling the human rights of the Venezuelan people".

"These oligarchs believed that they were untouchable," he told peasants in Trujillo state.

Chavez said this week that he had "unsheathed his sword"

"There are no untouchables in Venezuela. A criminal is a criminal."

The secretary-general of the Organisation of American States, Cesar Gaviria, has called on the Venezuelan authorities to respect Mr Fernandez's rights and recognise the important role he has played in Venezuelan society.

On Thursday, angry demonstrators surrounded an air force base to the east of Caracas waving national flags and shouting "Free Fernandez!" and "This is a dictatorship!"

"This is an escalation of violence by the government, which has arrived at the extreme of repression," said Carlos Feijoo, a retired oil worker joining the demonstration.

The United States described Mr Fernandez's arrest as a "very worrisome" development that would only increase the political and economic crisis which has beset Venezuela.

Further arrests threatened

Speaking after the arrest of Mr Fernandez, Mr Chavez was in defiant mood.

Ortega says opposition leaders are in danger

"One of the coup-plotters was arrested last night. It was about time, and see how the others are running to hide," he said. "I went to bed with a smile."

Mr Chavez urged the country's judges to not "be afraid to issue arrest warrants against coup-plotters".

One lawmaker from the president's party, Luis Velasquez, said about 100 opposition leaders were on an arrest list.

Both Mr Fernandez and Mr Ortega are wanted "for the crimes of rebellion, treason against the motherland, incitement, association with criminals and destruction of property," according to the arrest warrants issued by a Caracas judge.

Mr Fernandez was seized by members of the police intelligence service from a Caracas restaurant.