Reuters is saying 11 dead, so very much in nothing burger territory by local standards.
No evidence of vote rigging has been put forward by anyone, the US is crying that only an aggregate tally was released but that's very common because it protects individual neibourhoods against terrorist reprisal attacks. If they knew the opposition got exactly 200 votes, the 200 opposition voters would self identity, thus identifying government voters. The US set up aggregate elections this way in Afghanistan so it's a bullshit complaint, and the threat of US sanctions makes it painfully obvious that the US just hates the Venezuelan socialist government.

The electronic tallies took 6 hours to be verified, given the poor IT infrastructure that was hardly surprising. Some opposition figures were barred as witnesses, but that's not to say there were no witnesses at these stations just that an individual witness who turned up was kicked out. Likely for trying to disrupt voting.

Communists knocked down several statues in the city with sledge hammers, so you can probably see why the ruling party didn't let those individuals act as witnesses. Also the communists burnt election instructions last week. Why? Who knows.

It's a third world country, so recognise that security is always the priority.