Thousands of people marched in London on Saturday to urge British leaders to commit to broader acceptance of refugees fleeing conflict in Syria. In this photo, Syrian refugees hurry toward the Greek border with Macedonia on September 11, 2015. REUTERS/Yannis Behrakis

Thousands of people hoisted flags, lifted cardboard signs and hefted bright banners scrawled with hearts declaring, “Refugees Welcome" skyward on Saturday in central London.

They tweeted #refugeeswelcome to U.K. Prime Minister David Cameron en masse and marched through the streets to show solidarity with refugees around the world, and specially the 4 million people displaced by brutal conflict between the Islamic State group, rebel forces and the government of Syrian President Bashar Assad.

Their aim is to pressure the British government to expand policies to support refugees and welcome more migrants into the country.

Specifically, the march organizers requested that European leaders organize official transportation for refugees to safely travel to countries throughout the European Union. Presently, refugees may only request asylum once they have arrived in a host country and must find their own way there. The group also asked for expedited processing of asylum applications filed by Syrian refugees.

“We can’t allow any EU countries to close their borders or build fences. There needs to be Europe-wide consensus on providing help where it is so desperately needed, relieving pressure on the Mediterranean countries,” its organizers said on the Facebook page for the event.

The march has been dubbed Solidarity with Refugees and was organized by a coalition of organizations including Amnesty International, Stop the War Coalition and the Syria Solidarity Movement.

European leaders will gather in Brussels Monday to discuss how countries are handling the flood of refugees from Syria. Organizers hope that their action will urge leaders including U.K. Home Secretary Theresa May to permit more refugees to seek haven all across EU nations.

Citizens in Denmark, Finland, France, Austria and Romania hosted similar demonstrations on Saturday. Concerned citizens of other nations have used alternative methods -- Iceland’s government is weighing a proposal to accept 500 refugees after residents took to social media to criticize leaders for originally welcoming just 50 refugees into the country.