More than 200 environmental activists shut down traffic in Norwich city centre on Saturday to raise awareness about climate change.
Protestors from the Norwich branch of Extinction Rebellion staged a "critical mass bike ride" on St Stephens Street roundabout to cause disruption to cars and buses in the city centre.
Around 250 cyclists swarmed the streets, blocking off an entire lane of traffic by cycling "slowly but steadily" in a circular route from the Forum on Bethel Street round to St Stephens Street.
James Harvey, a spokesman for the group, said it was pushing for councils to declare a climate emergency.
He said: "The UK parliament has declared a climate emergency, now we need actions where the words are. We're non-violent and we don't want to cause any undue delays although there will of course be delays as a result. Disrupting people for 30 seconds to a minute is nothing for people to complain about when we're facing the emergency we are."
In April, Extinction Rebellion protestors closed off five major routes in London city centre, leading to the arrest of more than a thousand protestors.
Although police in Norwich said they were monitoring the disruption, the protest remained peaceful and did not lead to intervention by officers.
Jamie Osborne, activist and Norwich Green Party councillor, said the protest was well received by the public.
He said: "I think people realise that we're doing this because we're facing a climate emergency and want to draw attention to that. We want to draw attention to more sustainable forms of transport like cycling and public transport. There's a lot of public support for action on climate change."
However, others in the city said the protest sent mixed messages.
Karen Tills, from Norwich, said: "If they say we should be using more public transport then why are they targeting a main bus route? We know it's an important message but why do it in a way that causes a problem for normal people instead of the government or big businesses?"
The group said it would be holding critical mass bike rides in Norwich every third Saturday of the month and believed its numbers would continue to grow.
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