Greenpeace climbers unfurled an illustration by Shepard Fairey in Madrid's Reina Sofia museum early this morning to call for an immediate ceasefire in Gaza. The work shows a Palestinian child covered in blood with the caption "Can you hear us?" and the sign "unmute" in the centre. It is accompanied by another banner reading "CEASEFIRE NOW".

The illustration is based on the image taken by Gazan photojournalist Belal Khaled and is one of dozens of works by 30 visual artists from around the world who joined the Unmute Gaza movement to pay tribute to the photographers and journalists who, risking their lives, report from Gaza to draw attention to the nightmare of death, pain and destruction that is taking place in the area.

From the Guggenheim New York to Mumbai, UNMUTE GAZA has now reached over 83 cities and 30 countries. With an international roster - artists have been creating free assets for the public to print and paste in solidarity with photojournalists. The Committee to Protect Journalists has officially declared the official loss of 83 journalists and media workers, making this one of the deadliest conflicts for reporters in recent memory.

The organisations stress that the civilian population cannot be the victim of collective punishment, so it is necessary to stop the cycle of violence against innocent people. The Heads of State and Government, the European Union, the UN Security Council and all world leaders have a moral and legal obligation to act to ensure that a permanent ceasefire comes into effect, to guarantee the delivery of humanitarian assistance, to call for the release of all unlawfully and arbitrarily detained people, and to take the necessary steps towards a just and lasting peace in the part of the world that respects international law.