Courts in Belarus are hearing the cases of at least 70 protesters detained Tuesday in Minsk during an unauthorized rally marking the 90th anniversary of the country's declaration of independence.

Police say the courts Wednesday are hearing the cases of the activists, sentencing some to several days in prison and imposing fines on others.

Opposition activists say police surrounded hundreds of demonstrators, broke them up into small groups, severely beat some and bundled them off into waiting vehicles. Security forces detained a number of foreigners, including Poles and two Lithuanian journalists, who were held overnight and had their film confiscated.

Belarusian opposition groups have used March 25 for demonstrations protesting the policies of Belarus President Alexander Lukashenko, and to mark the 1918 founding of the Belarusian National Republic, later crushed by Soviet Red Army forces.

Lithuania's foreign ministry has called in the Belarusian ambassador in Vilnius to demand an explanation of the journalists' detentions.

Lithuanian President Valdas Adamkus also expressed deep concern over the incidents.

The United States and European countries have repeatedly accused Mr. Lukashenko of violating human rights, suppressing the opposition and silencing the independent news media.

Some information for this report was provided by AFP and Reuters.