A plane was grounded at Stuttgart Airport this morning over fears of an imminent bomb plot, German media reported.

It was feared that an attack may have been imminent after a passenger expressed fears over a conversation he heard, police said.

Possibly two or three people were questioned by police, according to Welt newspaper, following a disturbance.

They had been due to fly on the 180-seater Bulgaria Air plane at midday.

A federal police spokesman said: ‘During the routine departure check-out, a passenger told us that another passenger had threatened a bombing operation on the aircraft.

‘In ivew of the global political situation and the way in which the passenger met us, we had to take the threat seriously.’

According to another report there was an argument between three passengers which the crew regarded as a threat and police were called.

All take-offs and landings were temporarily suspended, but operations have resumed.

The flight to Varna, Bulgaria, is believed to have been evacuated and searched by police dogs and bomb disposal experts and is due to take off later.