The virus has killed at least 57 people worldwide

The International Ice Hockey Federation (IIHF) said it was "extraordinarily concerned" about the health risks caused by Severe Acute Respiratory Syndrome (Sars).

They have decided to cancel the 3-9 April tournament and have yet to decide whether this year's event will be rescheduled.

Switzerland, Sweden, Russia and Germany arrived in Beijing last week, while squads from the United States, Canada and Finland were due to travel this week.

The four teams already in China have been advised to return home as soon as possible.

MYSTERY BUG At least 57 people dead and 1,550 cases in 13 countries Originated in southern China Spread by international travellers

"The present situation [in Beijing] gives us reasons to be extraordinarily concerned," said IIHF President Ren� Fasel.

"The health of the athletes must always be our prime concern and with the new reports regarding the spread of the pneumonia, and the strong medical advice we received, this (cancellation) was really the only decision we could take.

"We were no longer in a position to guarantee the health of the athletes and team staff.

The IIHF said it would soon decide whether to hold the world championships at a later date.

Sars is a mysterious, and potentially fatal, pneumonia that is believed to have originated in China.

It has killed more than 50 people around the world, including 34 in China, and infected at least 1,400 others, of which 800 are in China.