Anti-war protesters have hailed Parliament's vote against British intervention in Syria as a "victory" as they gathered in Trafalgar Square to show their opposition to military strikes.
Around a thousand campaigners carried banners with slogans such as No Attack on Syria and Hands Off Syria and Syrian flags.
Speakers addressed the crowd from below Nelson's Column as tourists visiting central London looked on.
"Never let them say demonstrations don't work - our demonstration has worked," Lindsey German, convener of the Stop The War coalition, said to the cheers of protesters.
Stop the War coalition said that 5,000 people had turned out on a sunny and pleasant late summer day to back the protest.
Women with Syrian flags painted on their faces chanted "USA shame on you".
There were also several trade union and Communist flags with the hammer and sickle on display.
Mr Benn said: "Today is a victory of British public opinion over those who want war and the vote in Parliament last week was a result of all the demonstrations, like the one we had today, against war and in favour of peace.
"It is an indication that the British Government, which is a very right-wing government, has had to listen to public opinion. Chemical weapons are terrible weapons but when you think of all the thousands of people that would that have been killed by British and American troops in Afghanistan and Iraq you realise that it isn't true that another war would solve the problem."