Boris Johnson found it “utterly shocking” to witness the images and physical memorials of the genocide in Rwanda as he was led around a museum by survivors.

The Prime Minister bowed his head during a wreath laying ceremony at the Kigali Genocide Memorial, where the remains of an estimated 250,000 people are interred.

Mr Johnson wrote a lengthy message in the visitors’ book before pausing at the flame of remembrance marking 28 years since the 100 days that saw Hutu extremists claim the lives of around 800,000 Tutsi and moderate Hutus.

“It has been utterly shocking to see these images, and so many physical memorials, of the appalling and inexplicable genocide against the Tutsis,” it read.

“We must do everything we can to ensure that human hearts never again are allowed to breed such hatred.”