About 300 critics of long-serving President Nursultan Nazarbayev gathered in Kazakhstan's largest city Almaty to protest against what they say was a flawed election and to demand the release of jailed colleagues.
Opposition leaders called for democratic change and for the authorities to conduct a transparent investigation into the Central Asian state's deadliest violence in decades after riots last month in the oil-producing region of Zhanaozen.
They demanded colleagues jailed on charges of inciting the riots be freed.
It was the second peaceful protest since the Jan. 15 parliamentary election gave Nazarbayev's Nur Otan party an overwhelming victory.
The protesters had planned to gather at a monument to the 19th-century Kazakh poet and philosopher Abai but city authorities, who denied permission for the rally, fenced off the square and unarmed police stood guard. Demonstrators gathered outside a nearby hotel.
"We want change, peaceful change and democratic change. We want to be reckoned with," Bolat Abilov, co-chairman of the All-National Social Democratic Party, told the crowd through a megaphone.
A solitary Kazakh flag waved among a crowd that was swollen by the presence of journalists and plain-clothes police. A succession of speakers took the megaphone over nearly two hours before Muslim prayers brought the rally to a close.
Nazarbayev, a former Soviet Communist Party boss, has ruled Kazakhstan since before independence with little tolerance for dissent. This month's election admitted three parties to parliament for the first time, but observers from the Organisation for Security and Cooperation in Europe (OSCE) said it lacked any genuine opposition presence.
"The election wasn't legitimate. We want them to hear us," said Ravilya, a pensioner who stood in the crowd in temperatures of minus 10 degrees Celsius. "There are more police than people. It's a good thing they're armed only with sticks," she said.
Nazarbayev, 71, is popular among most of Kazakhstan's 16.7 million population for bringing stability that has made the country's economy the most successful in Central Asia.
But the riots in Zhanaozen, which officials say killed 16, shook that image of stability. Police used live rounds on crowds who set buildings ablaze in the town. Another person was killed in a nearby village the next day.
"We demand a just and large-scale investigation into the tragedy," Abilov said. "The president should promise that never again will weapons be used against citizens of Kazakhstan."
The prosecutor-general's office said this week that police generally acted within legal bounds when resorting to the use of weapons on Dec. 16, although four senior officers are being prosecuted for using excessive force.
Opposition leader Vladimir Kozlov and newspaper editor Igor Vinyavsky have been detained for two months pending trial on charges of fomenting social hatred and attempting to overthrow the constitutional order.
"We demand that authorities stop fighting against their opponents with such methods," Abilov said.