Prime Minister Prayut Chan-o-cha gave notice on Thursday that "all laws and all articles" will be used against protesters escalating the political conflict.
Gen Prayut gave his warning in a statement issued from his office, in the face of continuing street rallies by anti-government protesters demanding his removal and reform of the monarchy.
He said that the government and all agencies had tried to find a peaceful way out of the conflict, following legal procedures under a constitutional monarchy.
However, the situation had showed no sign of easing, despite the government showing its sincerity to solve the problems. Security agencies had done their job in maintaining peace and order, closely monitoring the situation and dealing with protests with the utmost care, in line with international standards, the prime minister said.
“The situation is not easing in a good direction and there is a tendency for conflict to escalate into more violence. If not addressed, this could cause damage to the country and the beloved institution, as well as to peace and the safety of people’s lives and property," Gen Prayut said in the statement, which was in Thai.
“It is necessary for the government and security agencies to intensify their actions by using all laws and all articles to take action against demonstrators who break the law and show no respect for the rights of other people.
"Action will be taken within the country’s area of jurisdiction and to international standards."
The statement did not specify whether this action would include use of Article 112, the lese majeste law, which forbids insulting the monarchy on pain of draconian prison sentences. Gen Prayuth said earlier this year that it was not being used at the request of HM the King.
Many thousands of anti-government protesters packed into Ratchaprasong intersection during their huge rally on Wednesday night, again announcing their demands for the prime minister's resignation and reform of the royal institution.