Hundreds of people marched in central London on Saturday to protest UK airstrikes against Syria.
Stop The War protestors marched from BBC Broadcasting House to Downing Street to denounce bombing raids carried out on targets belonging to the Islamic State (IS) terror group.
The Socialist Party supplied an open microphone for the event, with more than a dozen people lining up to speak to the crowd.
The Press Association reported that one speaker, who gave his name as Tony, labelled Prime Minister David Cameron "insane" and "evil" for pursuing a more aggressive approach.
He said: "You can't bomb your way to peace."
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Helen Pattinson, 24, who is part of a group that has been campaigning at schools, questioned the funding for military action.
She said: "How come they can find money to drop bombs on other countries to create refugees... but they can't find money for health, for education, and for young people to have a decent future?"
Nancy Taaffe, from the Socialist Party, told the crowd: "We've been here before people, haven't we?
"When we're told about peace and reconstruction, and then... we see the bodies coming back, we see the bombs in Baghdad market and the sectarian civil war erupted when they kicked the hornets' nest of the Iraq war."
She added: "We say no to the continued violence, we say no to the terror and we say no to the racism that is the fallout of this war."
Taaffe called on Labour politicians to bring a motion back to parliament to cease the air strikes.
She said: "We will back you up with a mass peace movement from outside."
Ursala Khan, 22, from Birmingham, said she was at the rally to show support for innocent Syrians who could be caught up in the strikes.
She said: "If I was in that situation - if I was in Syria - I would hope someone on the other side of the world would stand up for me."
Khan said she did not believe assurances that no civilians would be impacted.
She said: "There is always going to be collateral damage, people will always be killed."
Khan argued that there were other ways of tackling IS (also known as Isis, Isil and Daesh), such as finding out to whom they have sold weapons and oil.
She said: "I think (David Cameron) probably just wanted an easy option and probably just wanted to make more money. Typical Cameron."