MINSK, Belarus—Authorities in Belarus say that all but one of the 110 seats in parliament have been assigned after elections that critics of the vote say were tainted by improbably high turnout figures.

Central Elections Commission chairman Lidiya Yermoshina said Monday that only official turnout tallies would be considered, and downplayed assessments by independent observers. Yermoshina reported a preliminary turnout figure of 74.3 percent.

Parliamentary elections were held Sunday without the main opposition parties, which boycotted the vote to protest the detention of political prisoners and opportunities for election fraud.

The parliament in Belarus has long been reduced to a rubber stamp by authoritarian President Alexander Lukashenko. He has ruled the former Soviet nation since 1994. Western observers have criticized all recent elections in Belarus as undemocratic.