Around 20,000 people protested in Thailand's capital on Saturday against the government of former coup leader and Prime Minister Prayuth Chan-ocha, with many demonstrators also calling for reforms to the monarchy.

"Down with feudalism, long live the people," was one of the chants at the biggest demonstration in Bangkok since Prayuth took power in a 2014 coup.

Protests have been building in the southeast Asian country since mid-July, demanding the removal of the government, a new constitution and elections.