Russian-led forces have arrived in Kazakhstan at the request of the country's authoritarian leader, amid a crackdown on anti-government protests.
The interior ministry said 26 "armed criminals" had been "liquidated" and 18 security officers killed in the unrest, sparked by a fuel price hike.
A BBC journalist in the largest city Almaty shared video of heavy gunfire overnight on Thursday.
The UN, US, UK, and France have called on all sides to refrain from violence.
The internet is down, and little independent information is coming through. More than 3,000 people have been arrested, the interior ministry said.
According to local media, 70 checkpoints have been set up across the country.
In a statement on Friday, President Kassym-Jomart Tokayev said "constitutional order [had] largely been restored in all regions of the country" and that "local authorities [were] in control of the situation".
The president. who has blamed foreign-trained "terrorists" for the unrest without giving evidence, said the operations would continue until "the militants are completely eliminated".
- BACKGROUND: Kazakhstan country profile
- CONTEXT: Unrest explained
As the protests escalated, President Tokayev appealed to the Russian-led Collective Security Treaty Organisation (CSTO) for support. The bloc includes Russia, Kazakhstan, Belarus, Tajikistan and Armenia.
The overseas force reportedly sent about 2,500 soldiers to Kazakhstan. The CSTO says the troops are a peacekeeping force and will protect state and military installations. They will stay in the country for several days or weeks, the Russian RIA news agency reports.
The US state department said it was closely monitoring the deployment of Russian troops. "The United States and, frankly, the world will be watching for any violation of human rights," a spokesman said.
"We will also be watching for any actions that may lay the predicate for the seizure of Kazakh institutions."
The unrest began on Sunday when the cost of liquefied petroleum gas (LPG) - which many people in Kazakhstan use to fuel their cars - doubled, drawing protesters onto the streets.
The government has said that fuel price caps will be restored for six months. But the announcement has failed to end the protests, which have broadened to include other political grievances.
Kazakhstan is often described as authoritarian, and most elections are won by the ruling party with nearly 100% of the vote. There is no effective political opposition.
The bloodshed comes after President Tokayev sacked his cabinet on Wednesday in a bid to head off the demonstrations. He also fired his powerful predecessor, Nursultan Nazarbayev, who had held a national security role since stepping down as president.
Kazakhstan: The basics
Where is it? Kazakhstan shares borders with Russia to the north and China to the east. It is a huge country the size of Western Europe, dwarfing in land mass the other former Soviet republics of Central Asia.
Why does it matter? It has vast mineral resources, with 3% of global oil reserves and important coal and gas sectors. A mainly Muslim republic with a large Russian minority, it has largely escaped the civil strife seen in other parts of Central Asia.
Why is it making the news? Fuel riots have rocked the government, resulting in resignations at the top and a bloody crackdown on protesters.
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