A high-level international conference is underway in London to find "a pathway to peace" in Sudan, in the words of one of the hosts, the UK's Foreign Secretary David Lammy. Sudan's civil war began exactly two years ago causing what aid agencies call the world's worst humanitarian crisis. Britain is co-hosting Tuesday's summit alongside the African Union, the European Union, France and Germany.

At the start of the summit Lammy unveiled a £120m ($159m) worth of food and medical assistance. The EU and member states also pledged more than $592m in aid. Neither of Sudan's main warring parties - the Sudanese Armed Forces nor RSF - has been invited.

They will be represented instead by regional allies, some of whom diplomats say are fuelling the conflict. Among them is the United Arab Emirates (UAE), which is accused of arming the RSF, something it denies. So is Kenya. Charities say 30 million people in Sudan are in desperate need, and people are starving as a result of the war.

"Many have given up on Sudan – that is wrong – it's morally wrong when we see so many civilians beheaded, infants as young as one subjected to sexual violence, more people facing famine than anywhere else in the world... We simply cannot look away," Lammy said, opening the meeting on Tuesday. More than 12 million have been forced from their homes in Sudan and tens of thousands killed, amid widespread reports of sexual violence across the country and a genocide in Darfur.

In recent days, the Rapid Support Forces (RSF) launched an intense ground and aerial assault on camps for displaced people close to the city of el-Fasher in an attempt to seize the last state capital in Darfur held by their rival, the Sudanese army.

Zamzam, which has provided temporary shelter for an estimated 500,000 people, is now being systematically destroyed by fire from intentional arson by RSF forces, according to the Yale School of Public Health's Humanitarian Research Lab, which has analysed satellite images taken of the camp.