Mystery gas leak stops Sydney

Frustrated crowds were urged to be patient

Sydney has been temporarily thrown into chaos by a mysterious gas leak in the centre of Australia's biggest city.

The entire rail network was crippled after the leak was detected at Town Hall station shortly before 1400 local time (0300 GMT).

Thousands of people were evacuated and stations closed, as firefighters tried to pinpoint the source of the leak.

Rail services resumed only at 1800 local time (0700 GMT), but the source of the leak was still unknown.

New South Wales state Fire Brigades spokesman Superintendent Ian Krimmer was quoted by Reuters news agency as saying that gas odour readings by that time had become negligible.

However, further delays were expected as trains and free extra bus services struggled to cope with the huge increase in passengers.

Opposition politicians blamed the rail chaos on government neglect.

"It's scandalous that a city like Sydney can effectively be shut down because of its decaying, neglected rail network," opposition leader John Brogden was quoted as saying by the Sydney Morning Herald newspaper.

Sydney is home to some 4.2m people, and it is by far the biggest city in Australia.