Officials say one demonstrator died when an explosive device went off in his hands - the first confirmed fatality since the clashes began.
Autocratic President Alexander Lukashenko won 80% of the vote.
His main rival Svetlana Tikhanovskaya refused to accept the results, saying she was the real winner.
A lack of scrutiny - no observers were present - has led to allegations of widespread vote-rigging in the poll. Read more >>