The European Union criticised the arrest of two Venezuelan opposition leaders Tuesday following a controversial vote on a new assembly, saying it was a "step in the wrong direction".
The head of the European Parliament separately called for the bloc to look at sanctions against President Nicolas Maduro and his aides over the developments in the oil-rich South American nation.
Leopoldo Lopez and Antonio Ledezma, Venezuela's highest-profile opposition leaders, were both already under house arrest when they were picked up by the Venezuelan intelligence service early Tuesday.
"A few weeks ago we had welcomed the transfer of Leopoldo Lopez from his prison into house arrest," Catherine Ray, a spokeswoman for EU diplomatic chief Federica Mogherini, told a daily briefing when asked about the detention of the two men.
"We heard the news today and we believe it's clearly a step in the wrong direction. We expect more information from the Venezuelan authorities on their situation which is still unclear."
The EU on Monday said it had "grave doubts" about recognising the vote, and on Tuesday it again urged the government in Caracas to end a four-month crackdown on protests that has left more than 120 people dead.
"We keep calling on the government of Venezuela to work towards urgent confidence-building measures aimed at de-escalating the tensions and fostering better conditions for resuming efforts towards a peaceful negotiated solution," said Ray.
European Parliament chief Antonio Tajani said he had written a letter calling for action to Donald Tusk, head of the European Council which represents the 28 member states, and European Commission chief Jean-Claude Juncker.
"The constant violation of human rights, the brutal repression exerted by the Government cannot continue,” Tajani said in a statement.
He said the letters to Tusk and Juncker were "asking for the possibility of freezing the assets and imposing a travel ban to the EU to the members of the Venezuelan Government including its President, Nicolas Maduro and its entourage.
"The EU needs to stand for its values of democracy and freedom of expression also outside of its borders and make its voice heard," added Tajani, who heads the EU's only directly elected body.