A rare syndrome in children linked to Covid-19 is affecting youngsters with African heritage more than those who are white, research suggests, prompting "high vigilance" from doctors.

A cluster of cases of the new "hyper inflammatory disease" were detected in south east London, namely Woolwich, in early May.

The Covid-linked illness, said to be similar to Kawasaki disease, is thought to have affected around 75 to 100 children in the UK so far, with a 14-year-old boy treated at the Evelina London Children's Hospital sadly becoming the first British child to die from the syndrome.

Now, studies of young patients admitted to the Necker-Enfants Malades hospital in Paris found more than half (57%) of youngsters had African heritage, compared with 29% who were European and 10% who were Asian.

Coronavirus is already known to have impacted BAME communities disproportionately hard, and the researchers say their findings "should prompt high vigilance" among doctors, particularly in countries with a high proportion of children of African ancestry.

Professor Russell Viner, president of the Royal College of Paediatrics and Child Health, previously said the condition was very rare, but that it appeared to occur mostly after coronavirus infection.

The main symptoms of the condition are a high and persistent fever and a rash, while some children also experience abdominal pain and gastrointestinal problems.

Although some patients have required intensive care, others have responded to treatment and been discharged.

The new study from Paris found that all 21 children affected had gastrointestinal symptoms (abdominal pain, often with vomiting and diarrhoea), while other common symptoms were rash (76%) and inflammation of the heart muscle (also known as myocarditis, 76%).

The children were aged three to 16 and were admitted to hospital between April 27 and May 11, with 90% having evidence of recent Covid-19 infection.

Despite 17 patients (81%) needing intensive care, all patients were discharged home by May 15 with no serious complications.

The researchers said their findings "should prompt high vigilance" among doctors, particularly in countries with a high proportion of children of African ancestry.

They said more research was needed but factors such as social and living conditions, and genetic susceptibility to the illness, needed to be explored.