Thousands of demonstrators from the anti-capitalist Blockupy movement have cut off access to the European Central Bank (ECB) in Frankfurt to protest against policymakers' handling of Europe's debt crisis.

Clasping signs with slogans such as "humanity before profit", the protesters gathered in the rain to block roads including those leading to Deutsche Bank's headquarters in the city's financial district on Friday.

The crowd, estimated by police at roughly 2,500 protesters, was met by armed police wearing helmets and riot gear and accompanied by Alsatian dogs.

Trucks with water cannons stood by and a helicopter hovered overhead.

At least 20 protesters held up inflatable mattresses with the slogan "War Starts Here" written on them.

Police said some protesters had thrown stones and there were some clashes at the barricades, but the protest was generally peaceful.

Al Jazeera's Nick Spicer, reporting from Frankfurt, said that there is an overall feeling that there is such a heavy police presence that it is in fact the police that are occupying the bank.

"Later they will be going on to the Deutsche Bank, to protest what they see as land grabs in Asia, as well as [speculation] in food prices," said Spicer.

"They will also be going to one of Frankfurt's most important airports, to demonstrate their displeasure about the forced repatriation of refugees and racism as they see it." 

Europe's Blockupy movement was formed after the Occupy Wall Street movement in 2011.

'Prevent normal operations'

"The aim of this blockade is to prevent normal operations [at the ECB]," said Blockupy spokesman Martin Sommer, adding that some people who had tried to come to work had been sent home by the protesters.

Governments struggling with large debt burdens have cut spending and raised taxes, contributing to widespread recession across the euro zone, while many families are deep in debt or have lost their homes after property bubbles burst.

The German economy has been relatively resilient to the crisis.

Many of Frankfurt's banks have urged staff to take Friday as holiday after a state holiday on Thursday.

The ECB said it had taken measures to remain operational and ensure the safety of its staff.

The demonstration, held roughly a year after police detained hundreds of people for defying a temporary ban on protests at a similar four-day event in Frankfurt, preceded Europe-wide gatherings planned for June 1.

Source: Al Jazeera and agencies