MONTREAL - SCIENTISTS and amateur astronomers were combing the prairies in western Canada for a 10-ton meteorite that lit the sky and exploded with the force of 300 tonnes of dynamite, two experts from the Canadian Space Agency said on Tuesday.

The meteorite, seen on Thursday by thousands of people in a 700km radius, fell south-east of Lloydminster, near the border between Saskatchewan and Alberta provinces, astrophysicists Alan Hildebrand and Peter Brown said in a statement.

WASHINGTON - PLAYING doctor on the Web often leads people to mistakenly believe that they are suffering from rare illnesses, according to a study by researchers at Microsoft.

PARIS - UNIVERSAL and voluntary testing for HIV and early access to antiretroviral drugs could slash infections of the Aids virus by 95 per cent within a decade, a study said on Wednesday.