Bangkok, Thailand (CNN) -- Escalating violence in Thailand between protesters and government forces prompted the U.N.'s top human rights official to implore both sides to resume talks and work toward a peaceful resolution before the situation spirals "out of control."
"I urge leaders to set aside pride and politics for the sake of the people of Thailand," High Commissioner for Human Rights Navi Pillay said Monday.
"As the latest government deadline passes, there is a high risk that the situation could spiral out of control," Pillay said. "To prevent further loss of life, I appeal to the protesters to step back from the brink, and the security forces to exercise maximum restraint in line with the instructions given by the government. Ultimately, this situation can only be resolved by negotiation."
Clashes between the Red Shirt protesters and security forces continued to wreak havoc in central Bangkok late Monday, turning residential and tourist areas into a scene of chaos. At least 36 people have been killed since the fighting broke out Thursday, including two soldiers.
The Ministry of Public Health reported Tuesday that 65 people have died and more than 1,000 have been wounded since the protesters began flooding the streets of Bangkok on March 12 to demand new elections.
Despite a government-ordered deadline for demonstrators to leave their protest site by 3 p.m. (4 a.m. ET), members of the Red Shirt movement continued to defy the government through the night.
About 5,000 protesters remained in the area after the deadline passed, said Prawut Thavornsiri, a spokesman for the Royal Thai Police Operation center.
The government's objective is to protect civilians caught in the crossfire, Thai government spokesman Panitan Wattanayagorn said.
"Our objective is to secure the area, to prevent the elements that have weapons of war to attack the officers and attack the people," Panitan said. "We are communicating to the protesters for them to know that they will all be transported back home safely."
Earlier on Monday an airplane circling the demonstration area and a televised warning broadcast multiple times ordered protesters to vacate the streets immediately. The announcement said those who did not leave by the deadline would face a maximum sentence of two years' imprisonment for violating the order. But government officials have not said what they plan to do now that the deadline has passed.
Also Monday, officials at Vachira Hospital announced the death of Maj. Gen. Khattiya Sawasdipol -- a renegade general better known as Seh Daeng, which means Red Commander. Khattiya was shot in the head as he was being interviewed by journalists last week. It was unclear who fired at him.
Members of a radical faction that Khattiya headed told CNN they observed a three-minute silence when his death was announced. Some were in tears, as they described him. But it was unclear whether his death would spark more violence or dampen their resolve.
Thousands of anti-government protesters, known as "Red Shirts," have occupied areas of downtown Bangkok for weeks, calling for Thai Prime Minister Abhisit Vejjajiva to call new elections. The Red Shirts support former Prime Minister Thaksin Shinawatra, who was ousted in a 2006 bloodless military coup.
But the standoff erupted into street battles last week, as the government deployed security forces to disperse the protesters.
The violence has put Bangkok residents into a forced lockdown, trapped in their own homes as bullets cross the air indiscriminately. But Gary Burrows, who is from Britain, told CNN that staying at home is not always the safest bet. Waiting out the violence in his high-rise apartment on Petchaburi Road, Burrows thought he was safe from the raging gunfight outside -- until a bullet shattered a window.
"I woke up to reality that this is really serious, and I've got to get out of here now," he said.
Nearly 280 people have been injured in the bitter standoff between anti-government protesters and troops since Thursday, with 11 of the 36 deaths occurring in sporadic fighting throughout Sunday and overnight into Monday. iReport: Are you there? Send your images, video
Phil Robertson, deputy director of the Asia division of Human Rights Watch, called on militant groups among the anti-government protesters to stop using violence and on the government to follow U.N. principles on use of force and firearms. He said violence in densely populated neighborhoods is placing innocent civilians at risk.
"We're very concerned about these rapidly climbing casualties," Robertson told CNN. "We're very concerned that both of the sides, both the army and the Red Shirts, are in denial and digging in, and we think this is very dangerous."
Timeline of Thailand's political crisis
The government ordered schools and offices closed Monday and Tuesday "in order to ensure the safety of the public" after the protests paralyzed the city center.
Bangkok residents: We feel like hostages
At least nine international embassies in Bangkok -- the U.S., British, Belgian, Canadian, German, Japanese, New Zealand, Swedish and Australian embassies -- said they will remain closed until Tuesday at the earliest as a result of the clashes.
The government has declared a state of emergency in 22 provinces along with the Bangkok metropolitan area, Panitan said. It has also banned financial transactions with 106 companies and individuals over the protests, he said.
"The government has been under pressure to be more decisive in its action," a senior Thai government official told CNN. "We have been showing patience and restraint." That, he said, has upset those who want the government to take action against the protesters.