The demonstration started peacefully, with thousands of opposition protesters rallying on Baku's Qalaba (Victory) square to demand that President Ilham Aliyev's government step down amid allegations of widespread electoral fraud. Waving orange flags, the crowd chanted "Istefa!" (Resign!) and "Azadliq!" (Freedom!).
Azerbaijan's opposition parties had rescheduled the rally after they had failed to secure permission from Baku city authorities to stage it on 27 November.
The municipality gave the demonstrators only two hours to voice their protests. But after the deadline expired, opposition leader Ali Kerimli called upon the crowd to remain on the square and set up a permanent protest until its demands are met.
Kerimli chairs the reformist wing of the Popular Front of Azerbaijan (AXCP), one of the three parties that make up the Azadliq opposition coalition.
"Today is the time to make a decision," Kerimli said. "If you're ready to start a sit-in protest action, then I'm telling you: we will join you, we will be among you. Now, if you're ready, please sit down and let the entire world witness our struggle."
Kerimli's call triggered a swift reaction from the hundreds of riot police and Interior Ministry troops standing nearby.
Truncheon-wielding security forces rushed to disperse the crowd with the help of two water cannon, beating protesters and making a number of arrests.
Talking by phone from Baku, one protester told RFE/RL's Azerbaijani Service police managed to clear the square within minutes.
"We started our sit-in protest action and it was then that police moved [onto the square]," the unidentified protester said.
About 10 Injured
When RFE/RL asked if there were any protesters remaining on the square, the man said: "No, not on the square. Around the square, yes, people are standing and facing the police. Most of them are young men who are screaming: 'Resign!' Some people have sought refuges in the yards of the apartment buildings [that surround the square]. Police are chasing us. I have to run. They're beating people, they're chasing us!"
RFE/RL correspondent Ilqar Rasul says he saw at least 10 injured people either lying on the ground or being taken to ambulances. Among the wounded is Avaz Temirxan, the deputy chairman of the Liberal Party of Azerbaijan, who sustained a face injury.
Azerbaijan’s Turan news agency says police assaulted at least 10 reporters. The report could not be independently confirmed.
Other reports say some protesters hurled stones at the law enforcement officers, who were hiding behind shields.
Talking to reporters after security forces had asserted control over Qalaba Square, Baku deputy chief of police, Yasar Aliyev said at least 15 policemen received various injuries during the unrest.
But AXCP leader Kerimli blamed the violence on police, saying the protesters did not break the law.
“Police started using violence against the crowd five or six minutes before the authorized rally ended," Kerimli said. "There were 10,000 people on the square -- among them children, women and elderly people. Without even asking them to leave the square, [police] started moving. Thousands of people got hurt. We condemn this action, which unveiled the true face of the Azerbaijani government.”
Another opposition leader, Liberal Party chairwoman Lale Sovket Haciyeva of the Milli Birlik (National Unity) coalition, also accused police of provoking the clashes:
“Foreign governments have been trying to portray [President Aliyev’s] regime as a democratic one," she said. "But with what happened today, this will no longer be possible. Unbelievable things took place here. There were children and women [among the protesters]. Without a single warning and even before the rally ended, we witnessed a barbaric attack on the part of police.”
Azerbaijan’s independent APA (Azeri-Press Informasiya Agentliyi) news agency reports, however, that police attempted to obtain from AXCP Deputy Chairman Hasan Kerimov that the rally’s organizers put an end to the sitting protest. APA says police moved onto the square after the talks ended inconclusively.
The U.S. Embassy in Baku condemned Saturday's "unjustified and unprovoked" police violence and called upon the Azerbaijani government to take sanctions against those responsible.
Azerbaijan's opposition parties claim the 6 November parliamentary election was fraudulent and demand that new polls be organized.
Election observers from the Organization for Cooperation and Security in Europe (OSCE) and the Council of Europe have said the vote was flawed. But they have stopped short of calling for a new vote.
Authorities, in turn, deny the accusations of massive fraud. Following complains filed by opposition and independent candidates, they have, however, voided the outcome of the vote in four of Azerbaijan's 125 electoral constituencies.
The Central Election Commission on 23 November released final results that show the ruling Yeni Azerbaycan (New Azerbaijan) party winning 58 seats in the 125-member Milli Meclis, or National Assembly.
Independent candidates come second with nearly 50 seats. Only 11 seats went to the opposition.
The Constitutional Court has now seven days remaining to approve the results.
(RFE/RL Azerbaijani Service's correspondent Kenan Aliyev contributed to this report)
RFE/RL's complete coverage of the November 6, 2005, legislative elections in Azerbaijan and their aftermath.
Timeline: How The Elections Have Unfolded
A photo gallery of the Azerbaijan opposition protests in Baku on November 9, 2005.