Kazakhstan's President Kassym-Jomart Tokayev has ordered security personnel to open fire without warning in event of further disturbances, adding that those who failed to surrender would be "destroyed".
Up to 20,000 "bandits" had attacked the financial capital Almaty and were destroying state property, MrTokayev said in a televised address.
He said peacekeeping forces sent from Russia and neighbouring states had arrived at Kazakhstan's request and were in the country on a temporary basis to ensure security.
Mr Tokayev also thanked Russian President Vladimir Putin as well as the leaders of China, Uzbekistan and Turkey for their assistance in quelling the uprising.
The Kazakh interior ministry said in a separate statement that 26 "armed criminals" had been "liquidated" and more than 3,000 of them detained, while 18 police and national guard servicemen had been killed since the start of the protests.
"An anti-terrorist operation has been launched. The forces of law and order are working hard. Constitutional order has largely been restored in all regions of the country," Mr Tokayev said.
"Local authorities are in control of the situation. But terrorists are still using weapons and damaging the property of citizens. Therefore, counter-terrorist actions should be continued until the militants are completely eliminated," he added.
On Friday morning, Reuters correspondents saw armoured personal carriers and military servicemen in the main square of Almaty, Kazakhstan's largest city, where soldiers fired at protesters a day before.
A few hundred metres away, Reuters correspondents saw a dead body in a heavily damaged civilian car.
In another part of the city, they saw a ransacked store that used to sell ammunition. The correspondents also saw military vehicles and about 100 people in military uniforms at another square in Almaty.
The violence has been unprecedented in a state ruled firmly since Soviet times by leader Nursultan Nazarbayev, who had held on to the reins despite stepping down three years ago as president.
Police officers detain a demonstrator during a protest in Almaty, Kazakhstan. Source: AP
The uprising, which began as protests against a New Year's Day fuel price hike, swelled on Wednesday, when protesters chanting slogans against Mr Nazarbayev stormed and torched public buildings in Almaty and other cities.
Protesters accused Mr Nazarbayev's family and allies of amassing vast wealth while the nation of 19 million remained poor.
The unrest has seen the internet and banks mostly shut down across the country.
Mr Nazarbayev's hand-picked successor, Mr Tokayev, earlier this week blamed the unrest on foreign-trained terrorists.
The identity of the detained militants is being established and the possibility of them belonging to an extremist organisation is being investigated, Mr Tokayev's administration said on Friday.
Mr Tokayev will address the nation on Friday, his administration said, asking people in Almaty to limit their travelling around the city while the "search for the remaining hiding bandits is underway".
