About 10,000 protesters chanting "Freedom!" marched across Azerbaijan's capital Saturday, urging the government of this U.S. ally to step down and allow free parliamentary elections this year. Some of them carried portraits of President Bush.

The rally in Baku was the largest opposition demonstration in the former Soviet republic since October 2003, when one person died and nearly 200 were injured in clashes between police and demonstrators protesting vote-rigging in a presidential election.

Tensions have been building in this Caspian Sea nation in the run-up to parliamentary elections set for November. Some observers predict that Azerbaijan could experience a massive uprising similar to those that toppled unpopular governments in three other former Soviet countries -- Georgia, Ukraine and Kyrgyzstan -- in the past 18 months.

Supporters of several opposition parties chanted "Freedom!" and "Free Elections!" while holding placards with such slogans as "Down with robber government!" Placards with Bush's image included the call, "We want freedom!"

The rally was intended to draw attention to the opposition's push for election law reforms before the parliamentary vote and for access to state-controlled television. The opposition parties have accused authorities of rigging the 2003 presidential election in which President Ilham Aliyev succeeded his late father, Heydar Aliyev.

"Not only the opposition, but all people need democratic changes," Ali Kerimli, leader of the People's Front of Azerbaijan, said at the rally. "We demand free elections, and if the conditions for the free elections are not created, every village, every bloc will demand the government's resignation."

Aliyev's government "will never allow free elections, and it will mean its end," said opposition leader Panakh Huseinli. "The revolution is inevitable."

About 400 police officers in riot gear stood guard around a central square where protesters gathered, but they did not intervene and the rally ended peacefully.

Two weeks ago, police beat back opposition protesters who tried to hold a banned rally in Baku. Dozens were arrested.

Authorities in Baku initially refused the request from the People's Front of Azerbaijan, the Democratic Party of Azerbaijan and the Musavat party to allow Saturday's downtown rally, suggesting they instead hold it on the outskirts of the city. But after opposition leaders rejected that offer Friday, pledging to gather in downtown Baku anyway, authorities decided to approve it.

Azerbaijan, an oil-exporting, mostly Muslim country of about 8 million people, is the starting point of a new pipeline that officials in Washington say will reduce dependence on oil from the Middle East. The country is also a U.S. ally in the war on terrorism, with troops in Iraq.

A young protester in the Azerbaijani capital of Baku holds a picture of President Bush during a demonstration calling for free elections.