Giant prehistoric creatures invaded the streets of Norwich in a spectacular opening show for the Norfolk and Norwich Festival last night.

Huge fantastical beasts moved through the crowds while prehistoric birds flew overhead in what was the UK premiere of the show Invasion.

The performance, which started in Gentleman's Walk and moved around the market square before culminating in a performance at The Forum, was brought to Norwich by Dutch street theatre company Close Act, a group which has performed all over the world since it was founded in 1991.

Thousands of spectators packed the centre of Norwich for the 45-minute spectacle, becoming part of the performance themselves as puppeteers marched among them operating the fibreglass models.

The invasion began with giant insects flying high over the heads of the crowd, swooping close to the people perched on every available viewing point. Led by a 12ft witch on stilts, they made their way to The Forum, to be joined by a fantastical array of eyeball-headed robots, screeching dinosaurs and face-painted drummers.

Tonny Aerts, Close Act's artistic director, said the crowd was an essential part of the performance.

'The great thing about this large outdoor theatre performance is that it is not on a stage, and that makes it more interactive.

'We play inside an audience. The audience always react differently depending on which country we are performing in and that makes it more interesting as an actor because you get direct feedback.

'It is not a nice show to watch from a distance. You – as the audience member – are part of the performance.'

The Norfolk and Norwich Festival runs until May 26 and is bringing 16 days of art, theatre, music and more to the city.

Among the festival events this weekend is a garden party packed full of entertainment today and tomorrow at Chapelfield Gardens and Millennium Plain.

To see a gallery of pictures from Invasion, follow the link at the top right of this story.