Iraqi security forces hurled gas canisters and used sound bombs to disperse the thousands of Iraqi demonstrators, the followers of an influential cleric, in the heavily fortified government zone of the capital on Saturday.

One by one, demonstrators used ropes to pull down cement barricades leading to the gate of Iraq's Green Zone, which houses official buildings and foreign embassies.

They had come to protest the formation of the next government by Iran-backed parties. Security forces used gas canisters and sound bombs to repel the protesters as they approached the parliament building. Journalists for The Associated Press saw several people injured. A regular parliament session was expected. "We came today to remove the corrupt political class and prevent them from holding a parliament session, and to prevent the Framework from forming a government," said Raad Thabet, 41.

"We responded to al-Sadr's call. We will go to the Green (Zone). No matter the cost." The protesters are followers of influential Shiite cleric Muqtada al-Sadr, who called for the demonstrations against the formation of the next government by Iran-backed political groups.

Al-Sadr's party exited government formation talks in June, giving his rivals in the Coordination Framework alliance the majority they needed to move forward with the process. Many protesters wore black to mark the days leading to Ashura, which commemorates death of Imam Hussein, the grandson of the Prophet Mohamed and one of Shiite Islam's most important figures.