(CNN) -- Kazakhstan's President Nursultan Nazarbayev fired his son-in-law Tuesday from a government job, state media reported, 10 days after violent unrest broke out in the Central Asian country.
His decision to sack Timur Kulibayev, who managed a sovereign wealth fund, comes amid questions over the oil-rich nation's stability ahead of parliamentary and local elections next month.
A 20-day state of emergency was declared on December 17 in the city of Zhanaozen after clashes between police and striking oil workers left at least 14 people dead and 80 injured, state-run news agency Kazinform said.
The violence also spilled over to a nearby village, where protesters blocked a passenger train in a show of support for the oil workers, leading to at least one death.
The trouble came as the former Soviet republic celebrated its 20th anniversary of independence.
Speaking Friday to Kazakhstan's Khabar TV Channel, Nazarbayev said he planned to order Kulibayev to resign because of his failure to resolve the long-running labor dispute, Kazinform said.
Nazarbayev said "third parties" had taken advantage of the long standoff to organize the riots, said Kazinform, and expressed support for 1,800 workers who he said had been illegally sacked from the oil firm, Ozenmunaygaz. He also urged changes to the way the company is run.
"We should never forget that stability is the main condition for the success of Kazakhstan," the president is quoted as saying.
The violence erupted as police tried to clear protesters from Zhanaozen's main square, which had been occupied by workers protesting over low pay for more than six months, Russian state-run news agency RIA Novosti said. Eyewitnesses reported seeing police firing on unarmed striking oil workers, the agency reported.
A group of 48 European lawmakers wrote to Nazarbayev last week to condemn the violence. The workers' trade union puts the death toll at 50 to 70 people, with as many as 500 injured, they said -- a tally the government denies.
"We were horrified to hear that the riot police attacked the protesters, opening fire with live ammunition on the unarmed strikers and their families," the letter said. "We demand the withdrawal of all troops and an immediate genuinely independent inquiry into this atrocity, with those responsible being brought to justice."
International rights groups have expressed concern over the authorities' response in the days since the unrest.
Human Rights Watch said allegations of torture and abuse of detainees must be investigated after a man arrested in connection with the 16 December clashes died Thursday, apparently as a result of injuries sustained in police custody.
Journalist Elena Kostyuchenko, of Russia's Novaya Gazeta, who spoke with the man after his release, told HRW that he complained of being badly beaten during 24 hours in detention. He had visible bruises and was coughing up blood, she told HRW, but said he could not call a doctor because phones were cut off and was too afraid of rearrest to seek hospital treatment.
Rights groups say curbs on communications and freedom of movement in Zhanaozen are unjustified.
"By imposing such extensive restrictions, the Kazakh authorities make it hard to know what's happening in Zhanaozen. They risk undermining their stated commitment to transparency," Mihra Rittmann, Central Asia researcher at HRW, said in a statement.
The Committee to Protect Journalists accused the government in a statement last week of attacking and detaining independent journalists, as well as blocking communications, in order to suppress coverage of the unrest.
The U.S. State Department also said it was "deeply concerned" by the violence and reports of a clampdown on communications.
Meanwhile, the cleanup operation in Zhanaozen is still going on, according to state media.
Efforts to restore power, water and sanitation services in the city are continuing, Kazinform cited the prime minister's office as saying Tuesday, with 150 million Kazakh tenge ($996,000) allocated for the purpose.
Lilit Gevorgyan, a regional analyst with IHS Global Insight, said it was hard to get a clear picture of the current situation in the city because of the clampdown on information, but that things seemed to have calmed down.
This was likely partly due to a heavy Kazakh police presence and partly because of the president's pledge to help the sacked workers, she told CNN.
The trouble seems to have taken the authorities by surprise, she said, but they are now keen to prevent it spreading among Kazakhs unhappy over growing inequality.
While the country's natural resources have made a small elite vastly wealthy, many ordinary Kazakhs have not shared in the bounty, she said.
The government will also be aware of the swell of popular discontent in neighboring Russia, where thousands of people have demonstrated in recent days over alleged electoral fraud by Prime Minister Vladimir Putin's party, Gevorgyan said.
Against this backdrop, "the last thing (the authorities) need is people asking why some Kazakhs are billionaires while some don't have enough money to take care of their families," she said.
Nazarbayev, who has led the country since it declared independence, is popular among its citizens but has suffered health problems in recent months, leading to speculation about who might succeed him.
The firing of the president's son-in-law Kulibayev and other senior officials -- First Vice Prime Minister Umirzak Shukeyev was also relieved of his duties Monday, the presidential press office told Kazinform -- suggests Nazarbayev is trying to reassert his authority, Gevorgyan said.
Kulibayev was promoted in the summer and it was hinted he might be the anointed successor, but a lack of transparency in internal Kazakh affairs makes it hard to interpret his fall from grace, the analyst said.
Meanwhile, Nazarbayev's enduring popularity is the result in part of his long years in power, which have allowed him to prevent the emergence of any meaningful rival and control media coverage, she said.
The president has also acted shrewdly in putting himself on the side of the sacked oil workers, after an initially confused government response, she said.
The unrest is unlikely to have an impact on the elections, due to take place on January 15, she said, and the authorities will want to show investors in its energy sector that calm has been restored.
Kazakhstan has often boasted of its stability in a region that has seen its share of conflict. The ninth-largest country in the world by area, it has the largest economy of all the Central Asian states thanks mostly to its natural resources, according to the CIA Factbook.