Last week BBC News at Ten broadcast its first reports on a conflict the world cannot afford to continue to ignore. The United Nations says the scale of the crisis is on a par with Syria and Yemen, but has received minimal media attention. About 400,000 children in the Kasai region – an anti-government stronghold in the Democratic Republic of the Congo (DRC) – are at risk of death by starvation over the next couple of months if emergency food is not delivered.

A total of 7.7 million people – approximately 10% of the DRC’s population – are, according to the World Food Programme, on the verge of starvation; 3.2 million are in the Kasai region alone. To put it in perspective, that number is nearly 10 times the total of those living under siege from President Bashar al-Assad in Syria.

UN 'utterly horrified' by video appearing to show murder of two experts in Congo Read more

You don’t need to be an expert to work out that the Kasai crisis is not a result of drought, nor of flood or crop failure. It is a manmade one; and DRC president Joseph Kabila is primarily responsible for it.

Indeed, like Syria, the Kasai crisis began as a popular uprising against the president and his oppressive regime. Last August, one of Kasai’s most influential traditional chiefs, Kamuina Nsapu, revolted against Kabila over his abuse and corruption – and ordered all symbols of Kabila’s regime to be removed in protest.

Kabila, who succeeded his father Laurent-Désiré as president in 2001, and has been refusing to cede power after his second presidential term (which ended on 19 December 2016 and, constitutionally, should have been his last), responded with a basic but cruel form of warfare: the large-scale killing of civilians, including women and children, to keep rebelling villagers cowed. Nsapu himself was killed.

In February a video published by the New York Times showed forces loyal to Kabila walking down a sandy road in the Kasai region towards a group of presumed Nsapu supporters. The soldiers raise their weapons and open fire. The soldiers then saunter up to the wounded, blasting them in the head with assault rifles. Many of the victims look young; several were women, and none carried guns.

The UN security council mandated two experts, American Michael Sharp and Swedish Zaida Catalán, to investigate this incident as well as reports of gross human rights violations and the discovery of four mass graves. Both Sharp and Catalán, and their Congolese interpreter, Betu Tshintela, were kidnapped and killed in a government–controlled zone in March. Their Congolese driver, Isaac Kabuayi, and two unidentified motorbike drivers, are still missing.

Although Nsapu has been dead for over a year now, state-sponsored violence in Kasai continues almost unhindered, displacing 1.4 million people from their homes and destroying farming and food production, which has inflamed an already dire humanitarian crisis: over 5.4 million people were killed in the civil conflicts between 1998 and 2008.

Why are policymakers in London, Washington, Paris or Pretoria so quiet about Kabila's crimes?

UN investigators have since discovered an additional 76 mass graves, which raises serious questions about the international community’s responsibility to protect the weak. How many more Congolese people can Kabila kill before he is stopped? Why are policymakers in London, Washington, Paris or Pretoria so quiet about his crimes?

The issue before us is quite straightforward. The survival of 400,000 children in the Kasai region depends heavily on the mercy of the international community, and its policymakers in London, Paris, Washington, Brussels, Berlin, Ottawa, etc. The World Food Programme says it has only secured 1% of the $135m required to assist the people of Kasai until next June.

Beyond this, Congo needs an end to the Kabila regime that has turned the country into an “open-air prison” and a deeper international commitment to mediating Kabila’s peaceful departure. This would allow a transition to free, fair and transparent elections and at last bring stability to the country, and end the conflict in Kasai.

• Vava Tampa, who is Congolese, is the founder of Save the Congo, a London-based campaign for human rights in the Democratic Republic of the Congo