The Venezuelan government has taken six cable television channels off the air for breaking a law on transmitting government material.
The privately owned RCTV International, openly opposed to President Hugo Chavez, is one of those affected.
On Saturday the government had ordered RCTV to televise a government message, but the channel refused to comply.
The communications director for RCTV, Gladys Zapain, told AFP there was "no prior notification" of the move.
Last week RCTV, along with 23 other cable channels, was redefined by the government as a national, rather than international broadcaster.
As such, the channels would now be expected to carry presidential addresses and government campaign material in what is an election year in Venezuela.
'Battle of wills'
The government had urged cable services to drop channels ignoring the rules.
"They must comply with the law, and they cannot have a single channel that violates Venezuelan law as part of their programming," said the director of Venezuela's state-run telecommunications agency, Diosdado Cabello.
When the first opportunity to televise a government message was rejected by RCTV, it was ordered off air within a day.
The BBC's Will Grant in Caracas says there was only going to be one winner in such a battle of wills.
He says it is thought that the move is temporary at this stage, but that the government is unlikely to permit RCTV to broadcast again until the media group agrees to comply with the new law.
Opposition groups accuse Mr Chavez of trying to control the media and prevent coverage of political discontent.
RCTV moved to cable in 2007 after the Venezuelan government of Mr Chavez refused to renew its terrestrial licence.
Mr Chavez has in the past accused it of backing a coup attempt against him.