On Monday, Thai police said they had ordered an investigation of four news outlets under emergency measures launched last week and imposed curbs on the Telegram messaging app to try to stop protests against the government and monarchy for three months.

The announcement provoked anger from media groups and accusations by the government of Prime Minister Prayuth Chan-Ocha, the former junta leader who the protesters are trying to drive from the office, of an assault on press freedom.

Investigations of content from four media outlets as well as the Facebook page of a protest group have been ordered, according to a police document dated Oct. 16.

"We received information from the intelligence units concerned about the use and dissemination of parts of the content and distorted information to cause confusion and instigate social unrest," Police spokesperson Kissana Phathanacharoen told a news conference.

He said it was for the broadcast regulator and digital ministry of Thailand to investigate and take appropriate action, adding that there was no plan to curb the freedom of the press.

Putchapong Nodthaisong, a digital ministry spokesman, said it had requested court orders to take down content from the four media outlets and the Facebook page of the Free Youth protest group, among more than 300,000 pieces of content that it said over the past week violated Thai laws.

The Manushya Foundation, an independent group that campaigns for online freedom, called the measures an attempt to silence free media.

“Since the ban on protests did not work, the military-backed government hopes to create fear of telling the truth,” its director Emilie Palamy Pradichit said. "We urge resistance from the free media."

Last Thursday, the government ordered a ban on news and online information that could affect national security because, in the face of the growing challenge, it also banned political gatherings of more than five people.

On Monday, police chief Suwat Jangyodsuk also told reporters that he had ordered the digital ministry to restrict the Telegram Free Youth group, a messaging application that has been coordinated by protesters in recent days.

Putchapong, the spokesman for the ministry, declined to verify another document, apparently signed by him, asking internet service providers and mobile operators to completely "suspend Telegram."

Since they were banned on Thursday, protests have taken place every day, and Sunday's demonstrations have attracted tens of thousands of people in Bangkok and across the country. The police gave a figure in the capital of 20,000 protestors.

In the late afternoon of Monday, protesters were planning to gather again at three locations in Bangkok.

"We will prosecute everybody," said Deputy Bangkok Police Chief Piya Tawichai, adding that since Oct. 13, 74 protesters have been arrested.

Protesters are seeking the removal of Prime Minister Prayuth, accusing him of engineering the election last year to retain the power he first seized in a coup in 2014. He claims that the election was fair.

In demanding reforms to the monarchy to reduce the powers of King Maha Vajiralongkorn, the protestors have also grown more vocal. The Royal Palace made no comment on the protests or the demands of the protesters.

Prayuth said he wasn't going to quit. On Monday, speaking at Government House, Prayuth said he supported a proposal for a special session of parliament to discuss the situation. In parliament, his supporters have a majority.

We are simply asking people not to do wrong and destroy the property of the government and the people, "he said." "To protect the monarchy is what the government needs to do."