The European Union has imposed new sanctions on Belarus in an effort to persuade the authoritarian regime of President Alexander Lukashenko to free political prisoners.

Foreign ministers of the 27-nation bloc agreed Friday to freeze the assets and extend an EU travel ban on 12 more Belarusian nationals. They also banned 29 Belarusian companies from operating in the European Union. The new ban is in addition to the existing EU measures that keep more than 200 Belarusian political and business leaders in isolation for the government's persistent abuse of human and civil rights of its citizens.

At a meeting in Brussels Friday, EU foreign policy chief Catherine Ashton said she was “extremely concerned” about the fate of civil society in Belarus. She also said that the EU made it clear to Minsk that all political prisoners must be released.

Hundreds of people were arrested during the mass street protests following the Belarusian presidential vote in December of 2010, which western observers said was fraudulent.

Belarus has further riled the EU by executing two people convicted in last year's bombing of a metro station in Minsk. Fifteen people were killed and more than 100 were wounded in the attack. But the EU says the two suspected bombers did not have a fair trial. It also condemns capital punishment, which has been abandoned in the rest of Europe.

President Lukashenko has ruled Belarus for almost 18 years, cracking down on the opposition and repressing freedoms in defiance of warnings from western countries.