Almost 1,500 people were evacuated from a hotel and nightclub in central London overnight and two train stations were closed following a gas leak, authorities said Tuesday.
The area was cordoned off throughout the morning and staff in some nearby offices who arrived for work were later evacuated, an AFP photographer said.
"A ruptured gas main was discovered using detection equipment and high levels of natural gas were detected in the atmosphere," a London Fire Brigade spokesman said.
"As a precaution, approximately 1,450 people have been evacuated. They are from a hotel and a nightclub."
Charing Cross and Waterloo East train stations, which bring commuters into the capital, were also closed, while Underground trains were not stopping at Charing Cross.
Most of those evacuated had been in the 1,000-capacity Heaven nightclub when the alarm was raised about 2am (0200 GMT).
The club, a landmark on the London nightlife scene for almost 40 years, runs a popular all-night event on Mondays called "Popcorn".
The Strand, a major road running from Trafalgar Square to Waterloo Bridge, was also closed and people were asked to avoid the area.
A spokesman for the Cadent Gas company said an exclusion zone had been put in place "as a safety precaution", adding: "The Amba Hotel, nearby flats, offices and Charing Cross stations were evacuated."
It later said it had "found and fixed the leak" and was carrying out safety checks.
Westminster Council, the local authority, set up a rest centre at a nearby sports centre. It said 1,000 people from the nightclub and 350 residents and business personnel were evacuated.