Mid shot vender selling a yellow duck -- a protest symbol -- and yellow chicken for sale

Defiant pro-democracy protesters rally in Bangkok

Pro-democracy demonstrators in Thailand on Wednesday again took to the streets of the capital, even as the government escalated its legal battle against them, reviving the use of a harsh law against defaming the monarchy.

On Tuesday, police had issued summonses for 12 protest leaders to answer charges of "lese majeste", defaming or insulting key members of the royal family.

The offence is punishable by up to 15 years in prison.

Most of the protest leaders are already facing multiple charges, ranging from blocking traffic to sedition.

The lese majeste law is controversial, because anyone — not just royals or authorities — can lodge a complaint, so it had in the past been used as a weapon in political vendettas.

But it has not been employed for the past three years after King Maha Vajiralongkorn informed the government that he did not wish to see its use.

The king has not publicly commented on the law since then.

The protesters want the monarchy reformed to make it more accountable.

They also want Prime Minister Prayuth Chan-o-cha and his government to step down, and for the constitution, which was implemented under a military government, to be amended to make it more democratic.