Venezuela vote turnout was 32 percent by 6 pm - election board source

Ballots are seen in a box as they are counted by electoral workers at a polling station during the presidential election in Caracas, Venezuela, May 20, 2018. REUTERS/Marco Bello

CARACAS (Reuters) - Participation in Venezuela's controversial presidential election on Sunday was at 32.3 percent by 6 p.m. as most polling stations began closing, according to an election board source.

Turnout at Venezuela's last presidential election in 2015 was 80 percent, but the mainstream opposition called for a boycott of Sunday's vote, alleging it was rigged in favour of socialist leader Nicolas Maduro's re-election.