An angry mob stormed a bank in London today as the G20 protests turned violent. Masked anarchists smashed their way into the Royal Bank of Scotland branch in the City. They trashed equipment, daubed graffiti on the walls and threw a chair through a window. More than 4,000 demonstrators, most of them peaceful, gathered near the Bank of England to demand action from world leaders. But several hundred clashed with police, who were pelted with eggs, paint bombs and empty beer cans. Scotland Yard responded by cordoning off streets and sending in riot police and officers on horseback. There were 19 arrests for offences such as violent disorder, threatening behaviour and breach of the peace.