Sudan and one of the main rebel factions in Darfur have signed a ceasefire agreement in another step forward for United Nations attempts to broker peace in the region.
Sudanese government minister Amin Hassan Omer and Justice and Equality Movement (JEM) vice-chairman Arko Sulaiman Dahiya sealed the deal at a ceremony in Doha.
UN official Aichatou Mindaoudou described the ceasefire as a "major breakthrough" in the hunt for lasting peace in Darfur in western Sudan, which has been the scene of bloody conflict.
Over 2.8 million people have been displaced since the conflict began in 2003, and at least 480,000 killed as the government has tried to crush a rebellion by non-Arab Sudanese.
Khartoum stands accused of supporting irregular forces guilty of horrific human rights abuses against civilian populations as it tried to snuff out resistance.
The JEM had been the last big group to hold out against signing a ceasefire deal as set out by the Doha Document for Peace in Darfur.
It aims for a permanent peace agreement to end a decade of war.
Foreign Minister Alistair Burt's admission that the Cameron government has "supported" a survey of attitudes to US drone strikes in Pakistan's tribal areas amounts to a tacit admission of British involvement.