Bangkok, Thailand (CNN) -- The Thai government on Sunday extended a curfew in the capital and nearly a third of the country's provinces, but may shorten the hours when residents are required to stay off the streets, state media reported.
In his weekly television address, Prime Minister Abhisit Vejjajiva said officials would extend the curfew that had been scheduled to end Sunday morning, the Thai News Agency reported.
He said the exact time limits of the curfew would be announced Sunday afternoon, the agency said.
"Everything is calm and returning to normalcy," he said, according to the news agency.
Crews are cleaning up Bangkok's streets and government agencies and schools will reopen Monday, Abhisit said.
Officials imposed a curfew in Bangkok on Wednesday after government troops surged into Lumpini Park, where anti-government Red Shirt demonstrators had amassed.
After hours of intense street battles, five anti-government protest leaders were taken into custody. At least three more turned themselves in Thursday. Red Shirt leaders called off the protest, but some did not heed the call as smaller riots erupted in the city.
More than 30 buildings -- including a bank, a police station, a local television station and Thailand's biggest shopping mall -- were set ablaze.
At least 50 people have been killed in clashes in the past several weeks and nearly 400 people injured, government officials said.
The Red Shirt opposition members support former Prime Minister Thaksin Shinawatra, who was ousted in a bloodless military coup in 2006. They had been protesting for weeks, demanding that the current prime minister dissolve parliament and call new elections.