Network Rail told ITV News that there is no gas leak at London Bridge station and that train services are running as normal.
They added that four people were taken ill but the incidents were not related to each other.
More top news
A woman and man have been charged with murder after a baby was found unresponsive on a bus.
A "very dangerous" tattooed attacker who kidnapped a man before subjecting him to numerous assaults has been jailed for life.
The Duke and Duchess of Cambridge went salmon fishing in Canadian waters on the latest leg of their royal visit to the country.