Three nursery children are seriously ill in hospital after suffering kidney failure as a result of a suspected E.coli O157 outbreak. The two-year-olds were all members of the same nursery in Dunfermline, Fife, when they fell ill between the end of April and early May.

As doctors treated the children at Yorkhill Hospital in Glasgow, health officials were investigating the outbreak's source. The nursery, owned by the Careshare Group and is in the grounds of Lauder College's Halbeath campus, was closed yesterday for investigations.

Professor Bill McIntosh, Lauder College's principal, confirmed that two of the three sick two-year-olds were the children of college students. "We understand that preliminary reports... suggest the outbreak is not focused on the nursery itself," he added. "Obviously our thoughts and best wishes go out to the parents of the children and we pray for a speedy recovery."

E.coli O157 is a species of bacteria that could be lethal. It killed 21 elderly people and infected another 400 in Lanarkshire in 1996 in the world's worst recorded instance of E.coli poisoning. The source of outbreak was traced to John Barr's butcher's shop in Wishaw.

Dr Charles Saunders, a consultant in public health medicine for NHS Fife, said the source of the children's infections was not yet known.