Thai police set up roadblocks and closed 77 Bangkok train stations on Saturday as pro-democracy protesters continuted gathering in multiple locations around the Thai capital, defying an emergency decree banning gatherings for the fourth consecutive day.

The protesters used social media to arrange assemblies before police had time to block them. Authorities threatened legal action against Twitter and Facebook accounts that announced the protests, however fresh calls to action were posted on Saturday despite the state of emergency. 

The determined, youth-led protest movement is calling for Thai Prime Minister Prayuth Chan-ocha to step down, the nation's monarchy to undergo reform and the constitution to be amended to make it more democratic.

Read more: Thailand's young pro-democracy protesters challenge military and monarchy

Thai 'Hunger Games'

In an attempt to stay ahead of authorities, protest organizers advised followers to gather at stations outside the city center, where access was easier.

Hundreds gathered on Saturday in Bangkok's northern Lat Phrao district with helmets and gas masks, raising a three-finger salute adopted from the "Hunger Games" films as a symbol by the movement. 

Nearly a thousand protesters rallied in the western Wongwian Yai district chanting: "Long live the people, down with dictatorship!"

On Friday, after riot police dispersed largely peaceful protesters with high-pressure water cannon, the prime minister extended an emergency decree — which bans public gatherings of more than five people — until November 13.

The law gives authorities the power to restrict access to areas deemed off-limits.

Read more: Thailand's king should not reign from German soil, Berlin says

'Be prepared'

Police have meanwhile issued arrest warrants for more than 60 protesters, according to Thai Lawyers for Human Rights.

"We are calling on the government to ensure that no one is targeted, detained or charged with serious offenses for exercising their fundamental rights to freedom of peaceful assembly and expression," UN High Commissioner for Human Rights Ravina Shamdasani told reporters.

"Be prepared both physically and mentally for the demonstration and to cope with a crackdown if it happens," an online post from one of the pro-democracy movement's main organizing groups, Free Youth, said.

kw/rs (AFP, AP, dpa)