Thousands of protesters staged another anti-government rally in the Thai capital, Bangkok, on Sunday, demanding political reform.
Protesters want a revised constitution and also demand monarchy reform – a sensitive issue in Thailand.
Under Thai law, anyone who criticizes the royal family faces long prison sentences.
There have been almost daily demonstrations by students in recent weeks.
Several protest leaders have been arrested.
But organizers said they hoped Sunday’s rally would show broader support for change outside the student groups. Bangkok police said on Sunday night that about 10,000 people attended the protest.
“We want a new election and a new parliament of the people,” 24-year-old student activist Patsalawalee Tanakitwiboonpon told the cheering crowd.
“Ultimately, our dream is to have a monarchy that is truly under the constitution.”
Observers said Sunday’s protest at Bangkok’s Democracy Monument was one of the biggest anti-government demonstrations since Prime Minister Prayuth Chan-ocha took power in a 2014 coup.
They waved banners and shouted, “Down with dictatorship, long live democracy.”
Protesters are demanding that Mr Prayuth – a former general who won contested elections last year – stand.
The Jonathan Head of the BBC in Bangkok says that recent recording of the monarchy in the demands of the protesters has electrified the debate.
About 600 police officers checked the protest.
Nearby, dozens of supporters of the monarchy also staged a rally.
Last year’s elections were the first since the army took power in 2014 and for many young people they were seen as an opportunity for change.
But the army had taken steps to strengthen its political role, and at the elections Mr Prayuth was re-installed.
Mr Prayuth says the majority of Thais do not support the Protestants.
The last wave of protests began in February after the pro-democracy Future Forward Party (FFP) was dissolved by court order.
Protests were held but were quickly stopped by Covid-19 restrictions.
Tensions escalated in June when Wanchalearm Satsaksit, a leading activist who has been living in exile in Cambodia since 2014, went missing. The Thai government denied any involvement in its disappearance.
Student-led protests erupted on July 18, despite a ban on mass rallies during the country’s emergency. Rallies have been held almost daily since then.
Last week, senior student leader Parit Chiwarak, 22, was arrested and charged with charges including sedition, assault and holding an event that could spread an illness.