Akayev's whereabouts remained a mystery, although a statement purportedly from him said he was out of the country temporarily, denied he had resigned, and denounced what he called the opposition's "unconstitutional coup d'etat."
Opposition leader Kurmanbek Bakiyev emerged from the Parliament building and said he had been named acting prime minister and president.
"Freedom has finally come to us," Bakiyev told a crowd in Bishkek. Celebrations also were reported in southern Kyrgyzstan, where the popular uprising began earlier this month in the impoverished Central Asian nation.
Gunshots rang out on a street in downtown Bishkek after dark Friday and helmeted police in bulletproof vests chased a rowdy group of youths as looting continued for a second day.
In another part of the capital, with its streetlights extinguished, shots were fired near the central department store on the main avenue where vigilantes and police were on duty against looters. Police fired into the air to warn off a group of looters, witnesses said.
"The city looks as if it has gone mad," said Felix Kulov, a prominent opposition figure who was released from prison during Thursday's uprising and appointed coordinator of law enforcement.
At Akayev's lavish residence on Bishkek's outskirts, a security guard who identified himself only as Col. Alymkulov said the house was empty and untouched by looters.
Bakiyev's appointment as acting president was endorsed by a newly restored parliament of lawmakers who held seats before this year's disputed elections, which fueled protests against Akayev.
Bakiyev chose mostly prominent opposition figures for the posts of foreign, defense and finance ministers and chief prosecutor. For the job of interior minister, he picked Myktybek Abdyldayev, a former chief prosecutor who had been fired Wednesday by Akayev.
He appointed them as acting ministers, thereby avoiding the need for approval by parliament's upper house.
Bakiyev also signed an order appointing a communications minister and governors of the northern Chui and the southern Osh and Jalal-Abad regions, which were the epicenter of anti-Akayev protests.
The new leaders' immediate challenge in the strategic nation — it has both Russia and U.S. military bases and borders on China — was in halting vandalism and looting that left major stores in Bishkek gutted and damaged by youths who roamed the capital overnight. Kulov urged police, who have virtually disappeared from the streets, to return to work or face punishment, but he acknowledged few had shown up.
"It's an orgy going on here," Kulov told reporters. "We have arrested many people, we are trying to do something, but we physically lack people."
A shopping center on the main avenue was destroyed by fire and strewn with wreckage, as smoke hung in the air. At another shop gutted by fire, children and the elderly searched through what was left after looting overnight. Cars were picked clean, their windows and tires gone.
After weeks of intensifying protests in the south, propelled by widespread anger over the disputed elections, events moved quickly on Thursday and Friday, with crowds taking over government buildings in the capital with little resistance and the sudden flight of Akayev.
The Red Cross reported dozens injured in the turmoil Thursday, while lawmaker Temir Sariyev said three people had been killed and about 100 injured overnight.
"An unconstitutional coup d'etat has been staged in Kyrgyzstan," Akayev said in the statement distributed to some media in Kyrgyzstan.
"My current stay outside the country is temporary," the statement said. "Rumors of my resignation are deliberate, malicious lies."
In the e-mailed statement, with the sender listed as the Kyrgyz presidential press service, Akayev said he had given orders not to use force during the uprising, ignoring the advice of his aides, and that he had left the country to avoid bloodshed.
"I had sufficient forces at my disposal, which were ready to prevent the unrest," Akayev said. "But as you recall, from the very beginning of the unrest in the southern areas of the country, I firmly stated that I would not use force against my people."
Akayev's spokesman, Dosali Esenaliyev, said he did not know of the statement's existence, and its authenticity could not be determined.
The Russian news agency Interfax said Akayev and his family were in neighboring Kazakhstan, but it later cited unspecified sources as saying he had left that country.
Kulov said Akayev "had a chance to resign, but he fled."
"He wanted to go to Russia, but the Russians didn't accept him," he said.
Russian President Vladimir Putin said the Kremlin wouldn't object if Akayev wants to go to Russia. Foreign Ministry spokesman Alexander Yakovenko said Moscow doesn't know where Akayev was.
Bakiyev told the crowd in Bishkek that Akayev was "not on the territory of the republic. I don't know where he is."
Akayev's departure made Kyrgyzstan the third former Soviet republic in the past 18 months — after Georgia and Ukraine — to see popular protests bring down long-entrenched leaders widely accused of corruption.
Putin, on a visit to Armenia, said "it's unfortunate that yet again in the post-Soviet space, political problems in a country are resolved illegally and are accompanied by pogroms and human victims."
He urged the Kyrgyz opposition to quickly restore order, and praised them for helping develop bilateral ties during their earlier work in the government.
The 60-year-old Akayev had led Kyrgyzstan since 1990, before it gained independence in the Soviet collapse.
The takeover of government buildings followed similar seizures by opposition activists in the country's impoverished south. The protests began even before the first round of parliamentary elections Feb. 27 and swelled after March 13 run-offs that the opposition said were seriously flawed. The ballots put Akayev's son and daughter in parliament.
Several thousand people in the southern town of Jalal-Abad celebrated Akayev's ouster, said Gamal Soronkulov, opposition chief of security in Jalal-Abad. He said police started patrolling the town and that security has been stepped up to avoid the looting that plagued Bishkek.
The town's main square has been renamed Liberty Square, Soronkulov said. Jalal-Abad saw the first seizure of a government building by the opposition on March 4.
Opposition supporters in Osh, Kyrgyzstan's second-largest city, were preparing to hold similar celebrations Saturday, a police official said.
There was no sign the new leadership would change policy toward the West or Russia.
Acting Foreign Minister-designate Roza Otunbayeva said she would recall the country's ambassador to the United States, Baktybek Abdrisayev, who has refused to recognize the new government.
Kyrgyzstan has been a conduit for drugs and a potential hotbed of Islamic extremism. There was no indication, however, that the opposition would be more amenable to Islamic fundamentalist influence than Akayev's government has been.