Prime Minister Prayut Cha-o-cha has pleaded for calm and patience from security authorities deployed at the Democracy Monument where thousands of demonstrators are demanding the ouster of the government.
Deputy government spokeswoman Traisuree Taisaranakul said on Sunday that the prime minister had told authorities to be patient and show restraint if they were challenged by any protesters.
Gen Prayut also stressed that authorities must avoid violence against participants at the rally, but said the protesters must not violate the rights of other people.
Police deployed 600 officers from the Metropolitan Police Bureau to maintain law and order during the protest organised by the Free Youth and Free People groups. They are making three demands, including the dissolution of the House.
Other security authorities, including those in plain clothes, were present at the rally on Ratchadamneon Avenue.