Three giant camps in South Sudan are already hosting 70,000 people who fled from the north. They bring with them tales of attacks by air and land by the Sudanese armed forces. Many of the children arrive severely sick and malnourished, but the camps are already stretched to

breaking point

. Having adequate water supplies and making room for this fresh influx will be hard.

Four days of celebrations have begun in Britain to mark the Diamond Jubilee of the Queen's reign. The formal ceremonies opened with a 41-gun salute outside the Tower of London to mark the anniversary of her

coronation

. The Queen herself went to the races and saw the horse Camelot win the Epsom Derby. Nicholas Witchell was there.

In 1900, a horse called Diamond Jubilee won the derby. One hundred and twelve years later, the derby marked the official start of the Diamond Jubilee weekend of celebrations. Tomorrow 1,000 boats will

form up

on the Thames in the biggest river

pageant

for several centuries. On Monday, stars will be performing at a concert outside Buckingham Palace. And on Tuesday after a service of thanksgiving at St Paul's Cathedral, the Queen will ride in a carriage procession from parliament back to the palace.

The American Secretary of State Hillary Clinton has urged countries taking to exploit the resources of the Arctic to agree what she called the "rules of the road" to prevent future conflicts. Speaking in Norway, Mrs Clinton called on fellow Arctic nations to work together to ensure environmentally responsible development.