Police were called in after a Norfolk County Council meeting was delayed by protestors against a new road storming the council chamber.
The demonstration was over a new link road to the west of Norwich to link the city's northern and southern bypasses.
The protesters from the environmental group Extinction Rebellionhave been throwing paper aeroplanes and chanting in the council chamber.
The full county council meeting was due to start at 10am but didn't get underway until 2pm.
Click to watch a report by ITV News Anglia's Emily Knight
A spokesperson for Extinction Rebellion, Rebecca Stott, said: "We are appalled by Norwich County Council's decision to approve the £2m in design costs for this project.
Norfolk County Council says the development of the Norwich Western Link is one of its top infrastructure priorities.
It would link the northern bypass of Norwich known as the Broadland Northway from the A1067 to the A47 west of Norwich.
The council says there have been sustained calls to fill in the ‘missing link’.