Thai Prime Minister Yingluck Shinawatra has dissolved the country's parliament and called a snap election.

However, anti-government protest leaders pressed ahead with mass demonstrations seeking to install an unelected body to run Thailand.

About 100,000 protesters marched through Bangkok, extending a rally that descended into violence before pausing late last week to honour the king's birthday.

Blowing whistles, they vowed to oust Ms Yingluck and eradicate the influence of her self-exiled brother, former prime minister Thaksin Shinawatra.

"At this stage, when there are many people opposed to the government from many groups, the best way is to give back the power to the Thai people and hold an election. So the Thai people will decide," Ms Yingluck said in a televised address as the protests resumed across Bangkok.

The protesters ignored her announcement, deepening nearly a decade of rivalry between forces aligned with the Bangkok-based establishment and those who support Mr Thaksin, a former telecommunications tycoon who won huge support in the countryside with pro-poor policies.

Protest leader Suthep Thaugsuban said he would lead a march to Ms Yingluck's offices at Government House as planned.

"We have not yet reached our goal. The dissolving of parliament is not our aim," the former deputy prime minister under the previous military-backed government said.

Ms Yingluck's Puea Thai Party won the last election in 2011 by a landslide, enjoying widespread support in the north and northeast, Thailand's poorest regions.

The pro-establishment opposition Democrat Party has not won an election since 1992.

Ms Yingluck, Thailand's first female prime minister, will stand again.

"She will definitely run," said Jarupong Ruangsuwan, head of her party. "We want the Democrat Party to take part in elections and not to play street games."

The Election Commission has not set a date for the vote, which must be held between 45 and 60 days of a dissolution, but it is likely to be held in early February.