Roaring engines, mysterious flying objects and eerie floating lights – action in the skies over the Norwich area has caused a stir among puzzled onlookers below.

The unusual noise and lights over places including Costessey, Horsford and Spixworth in recent days has sparked speculation on social networks, with some people even putting forward extraterrestrial explanations.

RAF Lakenheath has confirmed that F15E Strike Eagle fighter jets were flying over Norwich on Tuesday evening, but many readers reported also seeing glowing orange lights floating serenely in the sky at the same time.

Reader Steven Granados, of Old Catton, was one of several people to contact the Evening News about the strange goings-on.

He said: 'I looked out of my window and saw four orange balls flying in a line across the sky.

'These 'UFOs' did not look like planes and had no flashing lights – at the same time as seeing these orange balls I could hear the jets flying over the city but the sound of the jets was not coming from the direction of the balls.

'One by one the orange balls disappeared, I then saw three fighter jets circle in the sky and fly in the direction from where the orange balls came from.'

Mr Granados discounted the possibility of them being Chinese-style lanterns, adding: 'These were really high up, and you can usually tell the lanterns because they flicker. I'd be surprised if they'd been scrambling jets for lanterns.'

Staff Sergeant Stephen Linch said pilots from Lakenheath had been performing exercises as part of an annual training programme scheduled to finish tonight.

He said: 'To cut a long story short, whenever we deploy and people ask for air support we don't say 'Sorry, we can't do that because we are not trained to fly at night'.'

He added that the base was 'keen to be a good neighbour'and while the jets were loud, they had not broken the sound barrier.