Police were called to keep calm among passengers on a plane at Gatwick, who were kept on board for an entire day after their plane was diverted from Heathrow airport because of fog.

The Air India flight from Mumbai was originally due to land at Heathrow at 7.30am, but was diverted to Gatwick because of dense early morning fog.

The passengers were then forced to sit on the plane on the Gatwick runway for nine hours – just an hour's drive by coach from Heathrow – watching brilliant sunshine and clear blue skies out the windows.

A BBC World Service reporter on board, Rahul Joglekar, said the mood became heated as the crew failed to keep the passengers, who included small children and a heavily pregnant woman, informed about what was happening, and when if ever they would set foot on English soil.

"We continue to be stranded here without any information from the crew," he told the BBC.

Shortly afterwards the plane finally took off for Heathrow, just before 5pm.

The problem, according to a Sussex police control spokesman, was that passengers had "some issues" as the hours passed.

"We were called in support of Gatwick staff, but in the event did not have to intervene, we were stood down," he said.

Apparently the original crew was out of flying time, and once the decision was taken that the passengers would be landed at Heathrow, the plane had to wait for a new crew.

There was no explanation from Air India as to why the passengers could not have been transferred by road – a decision which Gatwick said was taken by the airline.