The interim government has warned looters will be shot after many shops in the capital were ransacked
Kyrgyzstan's President Kurmanbek Bakiyev has offered to hold talks with what he called the temporary government that has replaced his administration.
But Mr Bakiyev, who was forced to flee the capital Bishkek amid a bloody uprising, insisted he will not resign.
In a telephone interview with the BBC, Mr Bakiyev said he was in southern Kyrgyzstan but would not disclose his exact location.
The opposition says it has taken full power, under a former foreign minister.
AT THE SCENE
Rayhan Demytrie BBC News, Bishkek
Things are slowly going back to normal in Bishkek.
After reports of more looting overnight, this morning there are more police officers in the streets.
Several hundred people are still standing in front of the presidential building, where there is a list of those killed in the mass protests of Tuesday and Wednesday.
Today is a national day of mourning and Roza Otunbayeva, the leader of the opposition movement is to pay a visit to Bishkek's main hospital to visit some of the 1,000 people who were injured in the violence.
It has not made an official response to Mr Bakiyev's offer of talks.
The group, led by veteran politician Roza Otunbayeva, has declared Friday an official day of mourning for 75 people killed in the uprising.
Ms Otunbayeva is due to visit some of the wonded in a hospital in Bishkek.
Further gunfire was heard overnight, with Reuters news agency quoting the interior ministry as saying police were battling looters.
However the overall situation in Bishkek was calm on Friday morning, correspondents say.
'No plans to leave'
Mr Bakiyev, who came to power in the central Asian state's "Tulip Revolution" five years ago, fled the bloody clashes in Bishkek on Wednesday, reportedly to fly to the southern city of Osh.
But he insisted he was still the legitimate president and condemned the uprising, saying the new interim government was "completely incapable" of imposing order.
The opposition claim to be in control, but you can tell that there's no law and order. Our opposition is so weak, nobody believes them
"Armed people are strolling the streets of the capital - stealing things, looting and pillaging, killing people," he told the BBC's Russian service.
But he added: "If this so-called 'temporary' government that has appointed itself is prepared to begin negotiation talks, then I'm prepared to listen to them and see what they want."
In an earlier interview with Russia's Ekho Moskvy radio station he insisted he had "no plans" to leave Kyrgyzstan but admitted: "I don't have any real levers of power."
Mr Bakiyev's defiant statements followed a news conference held by opposition leader Roza Otunbayeva, in which she said her government - which would remain in power until elections are held in six months - was fully in control.
She said Mr Bakiyev was trying to rally support in his home region of Jalal-Abad and urged him to resign.
"What we did yesterday was our answer to the repression and tyranny against the people by the Bakiyev regime," she said.
The violence initially broke out in the provincial town of Talas on Tuesday and spread to Bishkek, where demonstrators marched on government buildings, and another town, Naryn, on Wednesday.
Kyrgyzstan is a strategically important central Asian state and houses a Russian base and a key US military base that supplies forces in Afghanistan.
The US says there are "limited operations" at its Manas base but support for its forces in Afghanistan "has not been seriously affected".
TIMELINE: KYRGYZSTAN UNREST
March 2005: Protests over disputed parliamentary election, dubbed the Tulip Revolution, lead to fall of President Askar Akayev; Kurmanbek Bakiyev appointed acting president and PM
July 2005: Mr Bakiyev elected president by a landslide
May 2006: Mass protests demand constitutional reform and more action to combat corruption
October 2007: Referendum approves constitutional changes, which the opposition present as a step towards authoritarianism
December 2007: Mr Bakiyev's Ak Zhol party wins parliamentary poll; opposition left with no seats
July 2009: Mr Bakiyev re-elected in vote criticised by monitors
January 2010: Opposition leader Ismail Isakov jailed for eight years for corruption, sparking opposition hunger strikes
April 2010: Clashes between police and anti-government protesters leave 75 dead
Ms Otunbayeva said the "status quo would remain" regarding the bases but that some questions had to be considered.
She also thanked Russia for its "significant support" and said she would be sending envoys to Moscow for talks.
Later another opposition leader, Omurbek Tekebayev, told Reuters that Russia had "played its role in ousting Bakiyev" and that there was a "high probability that the duration of the US air base's presence in Kyrgyzstan will be shortened".
Russian Prime Minister Vladimir Putin and Ms Otunbayeva have already held telephone talks. An extra 150 paratroopers are being sent to Russia's Kant military base, near Bishkek.
Moscow has denied playing any role in the unrest.
US President Barack Obama's adviser on Russia, Michael McFaul, insisted this was "not some anti-American coup".
A US envoy met Ms Otunbayeva late on Thursday in Bishkek, the state department said, and called for calm and the respect of "democratic principles".
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.