Rumors that Kazakhstan's founding president and apparent target of ongoing protests, Nursultan Nazarbayev, had fled the country are false, his press secretary said Saturday.

Spokesperson Aidos Ukibay said on Twitter that Nazarbayev was in "direct contact" with President Kassym-Jomart Tokayev, whom Nazarbayev hand-picked as his successor after stepping down in 2019.

Nazarbayev "calls on everyone to rally around the president of Kazakhstan to overcome current challenges and ensure the integrity of the country," Ukibay said.

He also warned against spreading "knowingly false and speculative information," likely referring to unconfirmed reports that Nazarbayev had left the country.

The 81-year-old former Kazakh leader has not made a public appearance since the start of protests earlier this week that erupted into violence.

On Friday, the official Belta news agency of Belarus said President Alexander Lukashenko and Nazarbayev "discussed in detail the state of affairs in Kazakhstan" but provided no further information.

Much of the anger appeared directed at Nazarbayev, who had ruled Kazakhstan since 1989 before handing over power but who is widely believed to have remained in control behind the scenes. Many protesters shouted "Old Man Out!" in reference to Nazarbayev, and a statue of him was torn down in the southern city of Taldykorgan.

Critics have accused him and his family of staying in control behind the scenes and accumulating vast wealth at the expense of ordinary citizens.

Rumors have swirled of infighting among the Kazakh elite, with speculation that Nazarbayev had fled the country. Tokayev also took over from Nazarbayev this week as head of the country's security council.

Long seen as one of the most stable of the five ex-Soviet republics of Central Asia, Kazakhstan plunged into chaos this week, prompting Tokayev to call in troops from the Russia-dominated Collective Security Treaty Organisation (CSTO), which quickly agreed to send several thousand troops.

Military aircraft have been landing in Almaty – where the airport has been closed to civilian flights until at least Sunday – delivering Russian paratroopers and hardware.

In a hardline address to the nation on Friday, the president said 20,000 "armed bandits" had attacked Almaty and he authorized his forces to shoot to kill without warning. He ridiculed calls from abroad for negotiations as "nonsense," saying: "We are dealing with ... bandits and terrorists. So they must be destroyed."

The initial cause of the protests was a spike in fuel prices, but a government move to lower the prices and the sacking of the cabinet failed to stop demonstrations from continuing.

The violence erupted when police fired tear gas and stun grenades at thousands protesting in Almaty late on Tuesday. The next day protesters stormed government buildings, including the city administration headquarters and presidential residence, setting them ablaze. A nationwide state of emergency was declared shortly thereafter.

The interior ministry said 26 "armed criminals" had been killed in the unrest. It said 18 security officers had been killed and more than 740 wounded. More than 4,000 people have been detained, including some foreigners, according to the ministry.

On Saturday Tokayev's office said he had declared a national day of mourning for Monday.

The full picture of the chaos has often been unclear, with widespread disruptions to communications, including blocking mobile phone signals and hours-long internet shutdowns.

In Almaty an uneasy calm pervaded Saturday and few people were out on the streets. The military continued to guard the square adjacent to the mayor's office that was stormed by protesters and left badly burned, firing warning shots whenever passersby were slow to heed warnings to stay away from a checkpoint.