Russia and its allies pledged to send troops to help quell protests in Kazakhstan that posed the biggest threat to the central Asian country’s leadership for decades.

Dozens of anti-government protesters were killed by security forces, police said Thursday, after President Kassym-Jomart Tokayev ordered an “anti-terrorist operation” to put down the demonstrations. Banks were ordered temporarily shut for the day Thursday. Tokayev imposed a state of emergency nationwide and internet access was cut in much of the country.

Thousands of protesters had taken to the streets around the country in recent days, seizing government buildings and killing several law-enforcement officials after fuel-price rises unleashed a wave of popular anger over falling living standards. 

Sending what Russia and the handful of other members of the Collective Security Treaty Organization called “peacekeeping forces” was a dramatic move by the Kremlin-led bloc to shore up a longtime ally in the region in the face of public protests. There was no immediate word on the size of the deployment, which followed reports of Kazakh security forces surrendering to demonstrators and a late-night appeal from Tokayev.   

Prices for uranium surged almost 8% amid the unrest in the world’s largest supplier of the nuclear fuel. Kazakh bonds and the tenge slipped. There was no sign of disruption to oil output, the central Asia’s country biggest export, however.

Kazakhstan’s central bank suspended operations of the nation’s banks and the stock exchange, according to spokesman Olzhas Ramazanov. For now, the halt is planned only for Thursday, he said. Tokayev ordered price controls on key fuels and banned exports of some farm products for 180 days to stem inflation, Interfax reported.

With the internet and other communications disrupted, it was difficult to get a clear picture of how successful the authorities’ overnight crackdown was in pushing back the demonstrators. Russia’s state-run Tass news agency published video of heavily armed troops in Almaty, the country’s former capital and largest city, firing automatic weapons. Authorities said they had regained control of the airport there late Wednesday. 

Citing “threats to the national security and sovereignty” of Kazakhstan caused “in part by intervention from abroad,” the six-nation CSTO decided to deploy forces for a “limited period with the goal of stabilizing and normalizing the situation in the country,” according to the brief statement from the alliance posted early Thursday morning on the Kremlin website. Neither the CSTO nor Tokayev’s government indicated what outside forces it blamed for the violence, which appeared to have started spontaneously.

The bloc is dominated by Russia and also includes Armenia, Belarus, Kazakhstan, Kyrgyzstan and Tajikistan.

The action marks the second major move by the Kremlin in as many years to shore up an ally facing upheaval. In 2020, President Vladimir Putin stepped in to back Belarusian leader Alexander Lukashenko’s crackdown on popular protests, which drew sanctions from the U.S. and its allies. The Russian leader now is involved in high-stakes negotiations with the U.S. and Europe over a simmering conflict regarding Ukraine. 

The Kremlin has regularly condemned street protests in former Soviet states, labeling them attempts by the West to use “color revolutions” to overthrow governments.