Kazakhstan’s president has authorised security forces to shoot to kill those participating in unrest, opening the door for a dramatic escalation in a crackdown on anti-government protests that have turned violent.

The Central Asian nation this week experienced its worst street protests since gaining independence from the Soviet Union three decades ago, and dozens have been killed in the unrest.

The demonstrations began over a near-doubling of prices for a type of vehicle fuel but quickly spread across the country, reflecting wider discontent with authoritarian rule.

In a televised address to the nation, President Kassym-Jomart Tokayev used harsh rhetoric, referring to those involved in the turmoil as “terrorists”, “bandits” and “militants” – though it is unclear how peaceful protests gathered steam and then descended into violence.

No leaders have emerged so far.

“I have given the order to law enforcement and the army to shoot to kill without warning,” Mr Tokayev said.

“Those who don’t surrender will be eliminated.”

He also condemned calls by some countries for talks with the protesters as “nonsense”.

“What negotiations can be held with criminals, murderers?” Mr Tokayev asked.

On Friday, Kazakhstan’s Interior Ministry reported that security forces have killed 26 protesters during the unrest, which escalated sharply on Wednesday.

Another 26 were wounded and more than 3,800 people have been detained.

A total of 18 law enforcement officers were reported killed, and more than 700 injured.

The numbers could not be independently verified, and it was not clear if more people may have died in the melee as the protests turned extremely violent, with people storming government buildings and setting them ablaze.

Amid the growing crackdown, internet service has been severely disrupted and sometimes blocked, and several airports closed, including one in Almaty, the country’s largest city – making it difficult to get information about what is happening inside the country.

Mobile phone service has been severely disrupted as well.

Mr Tokayev has also called on a Russia-led military alliance, the Collective Security Treaty Organisation (CSTO), for help, and troops began arriving on Thursday.

Their involvement is an indication of concern among Kazakhstan’s neighbours, particularly Russia, that the unrest could spread.

More skirmishes in Almaty were reported on Friday morning.

Russia’s state news agency Tass reported that the building occupied by the Kazakh branch of the Mir broadcaster, funded by several former Soviet states, was on fire.

But in other parts of the country life started to return to normal.

And the Almaty airport – stormed and seized earlier by the protesters – was back under the control of Kazakh law enforcement and CSTO forces, Russian Defence Ministry spokesman Major General Igor Konashenkov said on Friday.

The airport will remain shut until Friday evening, local TV station Khabar 24 reported, citing the airport’s spokespeople.

And hours before he authorised the use of lethal force against those participating in unrest, Mr Tokayev indicated that some measure of calm had been restored, saying “local authorities are in control of the situation”.

Mr Tokayev has vacillated between trying to mollify the protesters – including issuing a 180-day price cap on vehicle fuel and a moratorium on utility rate increases – and promising harsh measures to quell the unrest.

Worries that a broader crackdown could be on the horizon grew after Mr Tokayev called on the CSTO alliance for help.

A total of 2,500 troops have arrived so far, all of them in Almaty, Kazakh media reported, citing Foreign Ministry officials.

Kazakh officials have insisted that troops from the alliance, which includes several former Soviet republics, will not be fighting the demonstrators, and instead will take on guarding government institutions.

It was not immediately clear whether the foreign troops deployed thus far were at all involved in suppressing the unrest.

In his address to the nation, Mr Tokayev repeated his allegations that “foreign actors” along with “independent media” helped incite the turmoil.

He offered no evidence for those claims, but such rhetoric has often been used by former Soviet nations, most prominently Russia and Belarus, which sought to suppress mass anti-government demonstrations in recent years.

Kazakhstan which spans a territory the size of Western Europe, borders Russia and China and sits atop colossal reserves of oil, natural gas, uranium and precious metals that make it strategically and economically important – and the crisis sparked concern in many quarters.

Ursula von der Leyen, the European Commission president, said she was following the developments with a “great worry”, while French President Emmanuel Macron called for de-escalation.

In Germany, Foreign Ministry spokesman Christofer Burger said officials were looking into the reports of Mr Tokayev’s shooting order.

From Germany’s point of view, “it must be said very clearly that a use of lethal force, of live ammunition against civilians can only be a very last resort, particularly if military forces are deployed”, he said.

But China appeared to step up its support for Kazakhstan’s government on Friday.

Kazakhstan is a critical component in China’s “Belt and Road” overland connection to Europe and persistent unrest in the country could upend Beijing’s hopes for closer trade and political relations with the continent.

Chinese President Xi Jinping expressed his condolences to Mr Tokayev over the “large-scale riot”, praising him for having “decisively taken strong measures at critical moments and quickly calming down the situation”.

“As a fraternal neighbour and a long-term strategic partner, China is willing to provide necessary support within its means to Kazakhstan to help it get over this difficult period,” Mr Xi said.

Despite Kazakhstan’s vast resource wealth, discontent over poor living conditions is strong in some parts of the country.

Many Kazakhs also chafe at the dominance of the ruling party, which holds more than 80% of the seats in parliament.