Azeri police arrested dozens of opposition activists who tried to stage a protest rally in the centre of the oil-producing Muslim country's capital Baku on Saturday.
Riot police seized protesters and pushed them into buses near Fountains Square in Baku, where the opposition had wanted to hold a rally but failed to receive approval from authorities.
One of the opposition leaders said after completion of the protest that about 1,000 people had taken part and more than 200 were arrested.
"Today's protest has demonstrated that Azeri people want change and are ready to act for the sake of democracy," Isa Gambar, leader of the opposition Musavat Party, told Reuters by telephone.
Police officials declined to comment on the arrests.
The police detained about 150 people at opposition rallies in Baku last month. The protests were inspired by unrest in the Middle East and North Africa, but analysts believe a revolt in energy supplier Azerbaijan is highly unlikely.
Hundreds of protesters, including members of opposition parties and activists, were trying to get to the square when riot police detained them.
Demonstrators shouted "Resign!" and "Freedom!" before members of the security forces began pushing people into buses.
Some of protesters had banners saying: "Ilham, go away!", a reference to President Ilham Aliyev.
Gambar said there would be more such demonstrations.
"Our protests will continue. It's not ruled out that the next rally will be held on April 9," Gambar said.
Azerbaijan, an energy supplier to Europe and a transit route for US troops in Afghanistan, has been ruled by one family for nearly two decades since Soviet veteran Heydar Aliyev came to power in 1993. His son Ilham succeeded him in 2003.
Police had told the opposition earlier this week not to hold a rally on Saturday and an opposition spokesman said up to 15 activists were arrested ahead of the protest. Rights groups condemned the arrests.
"Our people don't have a right to express their opinion, they don't have a right to gather. It's unacceptable," human rights activist Arzu Abdullayeva told Reuters.
Human Rights Watch and Amnesty International have called for the immediate release of opposition activists.
"The arrests are the government's latest attempt to prevent the type of protests in North Africa and Middle East from spreading in Azerbaijan," Human Rights Watch said in a statement on Friday.