Sars isolates lab workers

China has isolated more than 600 people in Beijing, after a laboratory leak led to the first death from sars since last year's outbreak killed nearly 800 people worldwide.

Across the country, authorities stepped up surveillance against the disease, which is highly contagious, before a week-long holiday starting on May 1 when millions of people are expected to take to travel.

The 600 quarantined people, including 24 staff of the national centre of disease control, are under collective isolation or bound to their homes.