Further voting in Thailand's election is already scheduled for February 23 after problems with advance voting last Sunday, while the ballot in some southern areas may not happen for weeks. Voting ends at 8am GMT, but no results will be announced today.
National Security Council chief Paradorn Pattanatabutr said: "The situation overall is calm and we haven't received any reports of violence this morning. "The protesters are rallying peacefully to show their opposition to this election."
Voting in 13 of Bangkok's 33 constituencies was disrupted. Thirty-seven out of 56 constituencies in the south, where opposition to the government is also strong, suffered disruption. Polling elsewhere in the country was unaffected.
Voters in Thailand go to the polls from 1am GMT under heavy security in an election that could push the divided country deeper into political turmoil and leave the winner paralysed for months by street protests, legal challenges and legislative limbo.
The risk of bloodshed at the ballot remains high, a day after seven people were wounded by gunshots and explosions during a standoff between supporters and opponents of embattled Prime Minister Yingluck Shinawatra in a north Bangkok stronghold of her Puea Thai Party.
The usual campaign billboards, glossy posters and pre-election buzz have been notably absent this time, as will be millions of voters fearful of poll violence or bent on rejecting a ballot bound to re-elect the political juggernaut controlled by Yingluck's billionaire brother, Thaksin Shinawatra.