The freeze on Thursday adds to a travel ban agreed on by the EU in April.
The EU said in a statement that the targets of the restrictive measures included the justice, interior, information and education ministers, as well as the chief prosecutor and heads of electoral commissions in a number of districts.
Alexander Lukashenko, 51, dubbed Europe's last dictator by Washington, was re-elected with 83% of votes in March 19 polls, sparking protests.
The polls were condemned as fraudulent by election monitors from the Organisation for Security and Cooperation in Europe, and relations with the EU have plunged to an all-time low.
In April, the 25-nation European bloc extended a travel ban to cover the same officials and has threatened for some time to hit them financially.
The EU condemned polls in
March as fraudulent
The EU said it would act "by freezing all funds and economic resources of persons who are responsible for the violations of international electoral standards and the crackdown on civil society and the democratic opposition."
"The common position also specifies that no funds or economic resources shall be made available, directly or indirectly, to or for the benefit of the persons concerned," the statement said.
Since the March polls, in which Lukashenko's nearest rival, Alexander Milinkevich, won just over 6%, the EU has bolstered its support for the Belarus opposition.
Lukashenko has been in power in the former Soviet republic since 1994.