Thailand's embattled premier called Monday for a special session of parliament as protesters planned more rallies to demand his resignation, the release of jailed activists, and reforms to the monarchy.

More than 1,000 protesters took to the streets in Bangkok on Monday, the fifth day in defiance a government ban aimed at stopping three months of action to demand the ousting of Prime Minister Prayuth Chan-ocha and reforms to the monarchy.

As the pressure mounting up, Prayuth said on Monday that parliament - currently in recess - would be recalled to discuss how to reduce tensions.

"We support opening an extraordinary session to solve this conflict," he told reporters, warning protesters not to break the law.

"I request protesters rally peacefully. The government has already compromised to some degree," he said.

Prayuth said on Friday he was not quitting, and banned gatherings of more than five people was imposed under the state of emergency on Thursday.

The largely leaderless movement is calling for the resignation of Prayut - a former army chief and mastermind of a 2014 coup - as well as the re-writing of the military-drafted constitution they say rigged last year's election in his favor.

Most controversially, protesters are also making unprecedented demands to reform the powerful and ultra-wealthy monarchy.

They want the abolition of a draconian defamation law that shields King Maha Vajiralongkorn from criticism, greater transparency of royal finances, and for the monarch to stay out of politics.

The movement appeared to be gaining traction across the country with smaller protests taking place Sunday from Phuket in the south to Khon Kaen in the northeast.

(With input from agencies)