Forty people were arrested and dozens injured by police in central London on Tuesday, following a demonstration that was part of an internationally coordinated day of action, coinciding with the opening of the World Trade Organisation (WTO) talks in Seattle. Billed as a sister demonstration to the “J18” protest held in June at the time of the G8 Summit, the protest was much smaller with only 1,000 taking part, compared to the estimated 6,000-10,000 at the summer demonstration. This did not prevent police from maintaining a massive presence in the capital, including officers in full riot gear and helicopter backup.

A carnival atmosphere had prevailed throughout the day, with small protests at Downing Street, Trafalgar Square and Oxford Street. Violence only broke out in the early evening when more than 1,000 protesters arrived at Euston station.

The police had been preparing for days to clamp down violently against the protests. Earlier on Tuesday at least four people were arrested on suspicion of involvement in the summer's J18 protest. At Euston station, dozens of police riot vans blocked neighbouring streets. Police closed the station, leaving 500 protesters trapped inside, whilst other officers armed with truncheons and riot shields encircled the remaining demonstrators, herding them towards the closed station.

During the ensuing fighting, in which a police van was overturned and set on fire, police used snatch squads to pick out protesters from the crowd. More than 40 arrests were made for public order offences, possession of offensive weapons, violent disorder, threatening behaviour and affray.

Inside the station the trapped protesters had their names and addresses taken, and were photographed before being released. They face severe penalties under new public order laws. The chairman of the Metropolitan Police Federation commented, "This is tantamount to eco-terrorism and those responsible should face the full weight of the law."