Thousands of anti-government protesters have taken over key intersections in Bangkok, defying a ban on protests for the fourth day with chants of "down with dictatorship" and "reform the monarchy".
Prime Minister Prayuth Chan-ocha, a former junta leader the protesters seek to oust, is concerned about the spreading protests and the government wants to talk, his spokesman said on Sunday.
Demonstrations persist despite the arrest of dozens of protesters and their leaders, the use of water cannon and shutdowns on much of Bangkok's metro rail system in a bid to quell over three months of street action.
"Free our friends", the protesters called out as they stood in a rain, a mass of colourful ponchos and umbrellas. Some held up pictures of detained protest leaders.
Thai Lawyers for Human Rights say at least 80 protesters have been arrested since October 13 with 27 still being held. Police have not given an overall number.
Prayuth's spokesman said the prime minister feared the protests, which have spread across the country of 70 million, could be used by troublemakers seeking to instigate violence.
"The government wants to talk to find a way out together," spokesman Anucha Burapachaisri said. He did not specify with whom the government hoped to speak.
After the arrest of many of the protest leaders, previously unknown figures have emerged to lead crowds which organise by themselves.
Police took no steps to intervene as protesters took over Victory Monument and Asok, two of Bangkok's most important transport hubs.
They said there were around 10,000 people at Victory Monument alone. A spokesman said there was no plan to suppress the protest.
Protesters say Prayuth engineered last year's election to keep power he seized in a 2014 coup - an accusation he denies.
The demonstrations have also become more openly critical of King Maha Vajiralongkorn's monarchy, breaking a longstanding taboo, demanding curbs to its powers despite jail terms of up 15 years for anyone insulting the king.
During demonstrations by tens of thousands of people at multiple points across Bangkok on Saturday, protesters painted a flag on the road with "Republic of Thailand" written across it.
The Royal Palace has made no comment on the protests.
The government banned demonstrations in Bangkok on Thursday.
Across Thailand, demonstrations were being organised in at least 19 other provinces on Sunday.
Australian Associated Press