The motorcade of America’s UN ambassador was involved in a tragedy when it struck and killed a young child while the envoy was visiting Cameroon.

Reports said that an armoured jeep in Samantha Power’s motorcade hit and killed a young boy who had darted into the road.

The incident occurred near the small city of Mokolo, in northern Cameroon, where Ms Power, her aides and accompanying journalists were headed to meet refugees and others displaced by the years of brutal attacks across West Africa, the Associated Press reported.

Reports said the motorcade was travelling at speeds of up to 60mph (AP)

Ms Power said she learned of the death with “great sorrow”.

She said she met with the boy’s family to “offer our profound condolences and our grief and heartbreak”.

Ms Power returned to the scene of the bloody accident several hours later to meet the seven-year-old boy’s mother and father, while residents of his village stood by.

The incident happened as Ms Power was headed to meet refugees (AP)

The news agency said the motorcade was traveling at speeds of more than 60mph, while villagers lined up along the sides of the road. But when the boy darted on to the two-lane highway, there was no time for the sixth car in Ms Power’s convoy to react. The driver was Cameroonian.

At the moment of impact, a man could be seen running up the embankment, with his arms held high, to the street to try to stop the child. A Cameroonian helicopter traveling overhead as part of a large security contingent saw the collision.

The vehicle that hit the boy initially stopped but was ordered by American security forces to continue traveling through the unsecured area. An ambulance in the US caravan immediately attended to him.

The boy was rushed to a local hospital, though his condition was already hopeless, according to people familiar with the incident.