Protesters have disrupted Thailand's general election on Sunday, preventing voting in parts of the capital Bangkok and across the south of the country.

The Election Commission said around six million registered voters were affected by the closures of polling stations, but maintained that 89% of voting centres operated smoothly.

Some polling stations were completely empty, with ballot boxes held hostage by anti-government protesters kilometres away.

Many more ballot boxes were trapped in post offices and district offices, particularly in the south, where some provinces had to cancel the election entirely because of the disruptions.

Thailand's election commissioner Somchai Srisutthiyakorn was unable to cast his vote because there were no election officials at his polling station.

One elderly woman sitting in front of dozens of cardboard ballot boxes told Sky News: "We have been here since four o'clock this morning. Whatever happens, we will not let anyone cast a vote for this illegitimate, corrupt government."

Chuwit Kamolvisit, a high-profile independent candidate and anti-corruption campaigner, brawled with anti-government protesters who attempted to attack him while he tried to cast his vote.

The protests prevented voting from taking place in 438 of Bangkok's 6,671 polling stations, with no voting taking place at all in nine southern provinces. The government said there was no disruption in the north and north-east of the country.

Security has been heavy throughout Thailand, with large areas placed under a state of emergency because of the protests.

Security officials said around 130,000 personnel were deployed across Thailand on Sunday, including 12,000 in Bangkok.

Prime Minster Yingluck Shinawatra cast her own vote amid tight security. "Today is an important day," she said. "I would like to invite Thai people to come out and vote to uphold democracy."

Even if Shinawatra wins the election, there will not be enough MPs for a quorum in parliament, so by-elections will be needed before a government can be formed. The opposition is also likely to launch a legal challenge to the election.