Broadcaster Angela Rippon has returned from a British Red Cross mission to Zimbabwe and warned of impending disaster caused by famine and Aids.

She said she was moved to tears by the appalling scenes of poverty and disease.

Two successive poor harvests have left many facing starvation.

And a quarter of the population - nearly a half of those who can work the land - are infected with HIV.

We must put humanitarian need above politics and do what we can to prevent the death of a nation

Angela Rippon

Ms Rippon said: "In rural Zvimba district, one of the poorest in Zimbabwe, the evidence of an impending humanitarian catastrophe is all too clear.

"The Red Cross tells me that three children have recently died at their school desks.

"It is part of a wider picture where the numbers of dead in just this one district have more than doubled from an average of 14 a month last year, to 36 a month now."

She said the scenes made her "angry and helpless" when she realised the scale of the humanitarian effort required to save lives.

HIV/Aids in Zimbabwe

One in four infected 2,000 die per week More than 640,000 children orphaned by it 42% of workers crippled by it

The broadcaster, vice president of the British Red Cross, travelled to Zimbabwe earlier this month and is appealing for British donations to help the charity's work in the country.

Experts have predicted that famine could grip the nation by September.

Ms Rippon added: "Food prices are rocketing, putting the cost of even basic items such as bread, milk and sugar beyond the reach of most people."

On her trip, she met eight families, including one which she described as offering a "bleak snapshot" of the horror encompassing the country.

Begging porridge

Two children aged two and four are dying with Aids and have no energy to play.

They are being looked after by their 54-year-old grandmother - the only member of the family able to.

Their mother died from the disease and their father was diagnosed as HIV positive.

Angela Rippon is vice president of the British Red Cross

The uncle, aunt and 18-month-old cousin are believed to be infected.

Ms Rippon said no-one in the family had eaten since begging porridge from a neighbour the night before.

The field that used to provide them with maize and vegetables is parched dry.

The Red Cross is the only charity to work across Zimbabwe without interference from the Mugabe regime, a spokeswoman for the charity said.

We can't just stand by and let people die

Angela Rippon

Red Cross volunteers help with tending the sick and educating the family in health care to minimise the spread of infection. And others distribute food to families.

The cost of a London Underground single fare - �1.40 - can feed an adult for a month, said the charity.

Ms Rippon added: "If you would like to help the work of the British Red Cross in Zimbabwe please call 08705 125 125 or visit www.redcross.org.uk."