Anti-war protesters brought traffic to a standstill in Newcastle as news of the start of war in Iraq broke out.
Trade unionists have been attending protests in Newcastle
Demonstrations in the Percy Street and St Mary's Place area caused massive tailbacks and brought morning traffic to a halt.
About 100 people took part in the vociferous anti-war demonstration, which began at 0800 GMT, in protest at American strikes against Iraq.
There was a large police presence, and traffic wardens were also on hand to help with the flow of vehicles.
The Stop the War protesters were due to end the demonstration with a candlelit vigil at Grey's Monument in the city centre 1800 GMT.
Late in the morning, protestors moved on to the bridge spanning the River Tyne between Newcastle and Gateshead.
A number of demonstrators then moved into the central roadway, and sat down, disrupting traffic.
Police moved them off the bridge to the south side of the river, into Gateshead.
The protestors headed to the Haymarket in the city centre for a lunchtime demonstration, where they were joined by trade unionists, council workers, and university students, swelling the crowd to about 250 people.
The protests are part of a UK-wide tactic of "civil disobedience".
Clare Toyne, of the student arm of the Tyneside Stop The War Coalition, said: "Passers-by have all been very supportive and there's been hardly any abuse from anyone.
"There's been a really friendly atmosphere throughout the day and we hope the candlelit vigil later today will be well supported.
"We are expecting a lot of support from students at the university."
A Northumbria Police spokeswoman said: "There have been a few minor demonstrations that are being monitored.
"We hope the demonstrators are mindful of the needs of the rest of the community."