The United States government has warned health authorities to be on the look-out for cases of meningitis among people recently returned from the Haj pilgrimage to Mecca.

It said there were at least three cases in New York alone, and it warned that vaccination does not offer complete protection.

The World Health Organisation says it has recorded two-hundred-and-fifty cases world-wide since the haj, including fifty-five deaths.

Most cases were in Saudi Arabia itself, though others have been reported in Britain, France, the Netherlands and Oman. There's also a separate outbreak in West Africa.

From the newsroom of the BBC World Service