Police are braced for more G20 violence in London after 87 people were arrested during protests marking the summit.
Metropolitan Police Commander Simon O'Brien warned there may be more clashes between officers and demonstrators as their focus moves to the summit meeting itself at the Excel Centre in London's Docklands.
On Wednesday, a protester, thought to be a man in his 30s, died after collapsing near the Bank of England.
The day also saw masked anarchists smash their way into a Royal Bank of Scotland (RBS) branch in central London and police chiefs said officers faced "high levels of violence" in isolated incidents throughout the day.
There were at least 87 arrests, including four for violent disorder, six public order offences and 11 for possessing a police uniform.
The Met said four people have since been charged. Three face a charge of possessing a bladed weapon, and one is charged with assault.
An angry mob trashed equipment, daubed graffiti on the walls and threw a chair through a window after more than 4,000 demonstrators, most of them peaceful, gathered near the Bank of England to demand action from world leaders.
Mr O'Brien, a member of the Met's command team for the G20 security operation, said small pockets of criminals were responsible for the outbreaks of trouble and would be tracked down.
But he added that the vast majority of participants were good-humoured.
Demonstrators are due to converge on the London Stock Exchange, but all eyes will be on the meeting of world leaders at the Excel Centre where protesters will be met with an extensive security operation.
