Protests have taken place around the world to demand intervention to end the fighting in Sudan's Darfur region.
Organisers of the Global Day for Darfur said events were taking place in 35 capitals to mark the fourth anniversary of the conflict.
Protests included a rally in Downing Street in London, as well as a march on Rome's Coliseum and a demonstration in the German capital Berlin.
Celebrities backing the campaign, such as George Clooney and Mick Jagger, have signed a statement accusing the international community of apathy.
Under the slogan "Time is up... protect Darfur", demonstrators will turn round some 10,000 hourglasses filled with fake blood to highlight the continuing violence in Darfur.
A letter addressed to the British Prime Minister Tony Blair called for him "to use your influence to push the international community to call for action".