Bangkok, Thailand (CNN) -- Concerns about further unrest prompted the Thai government to extend a state of emergency in 19 provinces, including Bangkok, for another three months Tuesday, officials said.
But the government revoked emergency rule in five other provinces where security threats have diminished enough that normal laws should be able to handle them, government spokesman Panitan Wattanayagorn said.
The emergency law empowers the military to take charge of security.
Thai Prime Minister Abhisit Vejjajiva imposed it amidst political unrest in April, shortly after Red Shirt anti-government demonstrators broke into the country's parliament.
Speaking on nationwide television in April, he said the emergency law's "purpose is to restore peace and order and to stop the spreading of false information to the Thai public."
Human rights groups have raised concerns about the emergency decree.
In a letter to Abhisit last month, Amnesty International said it restricts free expression and "essentially codifies immunity from prosecution for officials who committed human rights violations so long as they can claim to have done so within the section's broad terms."
More than 80 people died and 1,500 others were injured in the unrest, which included intense street battles between protesters and government troops. More than 30 buildings -- including a bank, a police station, a local television station and Thailand's biggest shopping mall -- were set ablaze.
The Red Shirt opposition members support former Prime Minister Thaksin Shinawatra, who was ousted in a bloodless military coup in 2006. They protested for weeks, demanding that Abhisit dissolve parliament and call new elections.