4.44pm:
Things are turning "very nasty" on Queen Victoria Street, according to Paul Lewis. He says protesters trying to sit down in protest have been "pounded" by riot police with batons trying to drive them back towards the Bank of England.

"I've just seen a girl unconscious being carried away, her whole face drenched in blood," tweets Paul.

4.28pm:
On Twitter, Snufkin21 says Stop the War protesters booed the media present "for hyping up the G20 violence". The huge media presence has been criticised by a number of people on Twitter who believe it's encouraged extreme elements to "play to the gallery".

4.15pm:
The "hardcore" protesters have broken through police lines and have made their way to an unboarded HSBC branch on Queen Victoria Street, says Guardian reporter Paul Lewis. An anarchist flag has been raised on an office block opposite the branch, he adds. The Press Association reported a fight on the same street between two men - one wearing a suit - which was broken up by police.

4.07pm:
Police on horses have carried out two charges down Threadneedle Street in a bid to disperse protesters, says Alok Jha, who is at the scene. Alok said everything had been calm beforehand and demonstrators have not been impressed by the police response.

4.00pm:
This incredible photo shows how many photographers were outside the RBS branch, presumably waiting for something like this to happen.

3.37pm:
Stop the War coalition has arrived at Trafalgar Square. Islington North Labour MP Jeremy Corbyn has just addressed the crowd. All appears calm.

3.27pm:
Police have now confirmed 19 arrests today, 11 in relation to the armoured car incident, and the others as follows.

1 - threatening behaviour
2 - violent behaviour
1 - obstructing the highway
2 - breach of peace
1 - indecency
1 - possession of class A drugs.

Over at climate camp things are much more peaceful relative to RBS with people picnicking.

"If you don't like the violence elsewhere, come to climate camp. It's completely peaceful! And good fun!" tweets climate camp.

Sandra Laville says: "Families camped out relaxed police looking on. But will they let them stay?"

3.17pm:
Matthew Weaver says it's still tense outside the RBS branch.

Alok Jha tweets that things are also tense on Poultry, round the corner from the Bank of England, where protesters are being held back by police.

David Teather is still on Poultry, albeit in the rooftop garden of the Coq d'Argent restaurant with City workers, where he says: "A banker in pinstripe tells me he is lunching as an act of defiance."

3.05pm:
Police have relaxed the cordon around the Bank and allowed crowds to filter away along Queen Victoria Street.

Some demonstrators told the Press Association they had seen incidents of police brutality and complained that officers had occasionally "gone over the top".

"Cops clearly don't like Bob Marley just randomly charging the demo during 'One Love'," Lasthours tweeted.

(Guardian 'tweet feed')