The Venezuelan president, Hugo Chavez, has told the army to follow nobody's orders but his own.

On national television, Mr Chavez said troops should ignore judges and court rulings and obey only presidential decrees.

His statement came as a general strike against his government entered its third week.

Mr Chavez insisted he won't be forced from office

Reports say several main roads in the capital, Caracas, have been blocked by opponents of the president.

Riot police have been deployed and have used teargas to disperse demonstrators in at least one instance.

Rifle-toting police kept opponents and supporters of Mr Chavez apart on the key Prados del Este highway through the south of the capital, which has been blocked by opposition cars since dawn on Monday.

Opposition demonstrators banged pots and pans, and chanted "The government will fall! The government is going to fall", while stick-wielding pro-Chavez crowds lit fireworks and shouted back insults.

Mr Chavez has described Venezuelans who support the protest as "coup plotters", insisting he will not be forced from office.

His opponents accuse him of economic mismanagement and authoritarian rule.

Earlier Mr Chavez, deployed army troops to seize an oil tanker, anchored in Lake Maraca Ibo, in a gesture of defiance to opponents leading a general strike which is now entering its third week.

Two oil tankers had been loaded over the weekend, but 40 ships were still waiting on anchor off Venezuelan export terminals.