The protest march is organized by Azadliq (Freedom), Azerbaijan's main opposition coalition.
An RFE/RL correspondent at the scene reports that thousands of protesters were taking part. He says they include representatives of youth organizations. No violence was reported. There was a heavy police presence.
Azadliq says the 6 November elections were rigged and demands that the results be annulled. Monitors from the Council of Europe and the Organization for Security and Cooperation in Europe have also criticized the vote, saying it did not meet international election standards.
Preliminary results show the party of President Ilham Aliyev winning most of the 125 seats in the national parliament.
Azerbaijani election authorities yesterday annulled the outcome of the vote in two of the country's 125 constituencies. But they deny allegations of fraud.
November 9 Baku Protests
A photo gallery of the Azerbaijan opposition protests in Baku on November 9, 2005.