Tens of thousands of protestors took to the streets in London on Saturday, in what marked the beginning of six days of demonstrations before next week's G20 summit.
More than 150 organizations were represented at the "Put People First" march, during which protesters called for job creation, as well as better economic and environmental accountability.
London police estimated that 35,000 people attended the demonstration, which wound through the city toward Hyde Park.
Protesters called for an open and fair economic recovery plan ahead of next Thursday's meeting of the world's richest countries, which will focus on discussing solutions for the ongoing economic crisis.
"The whole economic meltdown ... There's a really good opportunity for governments to get together and invest in a sustainable future," said unemployed protestor Steve Burson, 49.
The Stop the War Coalition, Friends of the Earth and the Trades Union Congress were among the largest groups participating in the protest.
"They should be solving (the crisis) in the interest of working people," said Andy Bain, the president of the Transport Salaried Staffs' Association. "All the money is going to the rich."
Marchers booed and whistled as they filed past British Prime Minister Gordon Brown's office and residence at 10 Downing Street.
Police established a tight security cordon around a group waving anarchist flags. Anarchists and other groups have indicated that protests would turn violent before Thursday's meeting, which has led to strict security protocols for when world leaders arrive in the city.
Further protests are planned for Wednesday and Thursday, while teach-ins, lectures and other demonstrations have been scheduled throughout the week.
Protesters also took to the streets in other European cities on Saturday.
In Berlin, police estimated that 10,000 people were congregated at city hall, while another 1,000 people gathered in protests across Frankfurt, Germany's banking centre.
With files from The Associated Press
