Police in ex-Soviet Belarus detain youth activist

MINSK, Sept 15 (Reuters) - Police on Friday detained an opponent of Belarus's President Alexander Lukashenko on suspicion of belonging to a unregistered group, an opposition activist said.

Dmitry Dashkevich, a leader of the "Young Front" group, faces up to three years in prison if charged under legislation passed last year by the ex-Soviet state's parliament on grounds of boosting national security ahead of Lukashenko's re-election.

Dashkevich was detained in the eastern town of Mogilyov, where he had gone to visit an opposition activist sentenced to two years of enforced labour for spraying graffiti on walls.

"According to our information, Dmitry was arrested on grounds of illegal activities of Young Front as an unregistered organisation," Viktor Ivashkevich of the Belarussian Popular Front, one of Belarus's largest opposition groups, told Reuters.

"No charges have yet been laid. But he is being kept in custody."

Belarussian security bodies were unavailable to comment.

Legislation passed in the run-up to March's presidential election introduced stiff penalties for activities deemed to run counter to national security.

Lukashenko's landslide election to a third term was denounced by Western countries -- and by Belarus's opposition -- as blatantly rigged.

The outcome caused unprecedented demonstrations in the capital Minsk, broken up after four days.

More than 600 protesters were jailed for up to 15 days for public order offences and an opposition leader who challenged Lukashenko in the race, Alexander Kozulin, was sentenced to 5 1/2 years for hooliganism and incitement to mass disorder.

Kozulin's appeal is to be heard in a Minsk court next week.

The Minsk city court on Friday rejected an appeal from two members of the "Partnership" group convicted before the March election on charges of membership of an unregistered body.

Nikolai Astreiko had received a two-year sentence and Timofei Dranchuk one year in prison.