The protester who threw a fire extinguisher from the top of a building during Wednesday's student demonstrations could already be under arrest, police said last night as they began trying to identify those responsible for the violence in London.
The head of the National Union of Students (NUS) distanced the organisation from rioters who lit fires, smashed windows and threw missiles from the roof of Millbank Tower, the Conservative Party headquarters.
But another senior NUS official backed those who were arrested, saying students should embark on a campaign of "French-style resistance" against the Government's public-spending cuts.
"We have seen what happens in France – why can't we have something like that here," Mark Bergfeld, a graduate of Essex University, said, calling it "regrettable" the NUS had condemned those who stormed Millbank.
"They should really be condemning the cuts being carried out by this Government," Mr Bergfeld said. Students were advocating "direct action", "civil disobedience" and "occupations" some time before the violence that police have since suggested was "spontaneous".
The Facebook page of the Radical Workers' and Students' Bloc (RWSB) called on "all anarchists and militant workers and students to join us in forming a Radical Workers' and Students' Bloc on the demonstration, arguing for all those in education to fight the cuts based on the principles of solidarity, direct action and control of our own struggles".
A second Facebook group entitled "Call for direct action at "Fund Our Future: Stop the Cuts", with about 260 members, encouraged its members to bring black anarchist flags to the rally. It posted the message: "We need to show these working-class hating Tory elitists that we aren't taking their shit anymore! Don your Black Bloc and let's fight back in solidarity!"
Police trying to identify the culprits will analyse hundreds of hours of footage, including video from news channels. Most of the 50 people arrested were detained for trespassing, but officers want to prosecute more severely the rioter who was photographed hurling a fire extinguisher. Paul McKeever, the chairman of the Police Federation, said the man should be charged with attempted murder; the empty canister landed near officers. "We are seeing if there are more serious offences here," a Metropolitan Police source said. "Throwing something that big from that height certainly would be."
Student groups are already planning more direct action after attracting 50,000 people to the rally, far more than expected. Co-ordinated university sit-ins and mass protests are already being planned this month by the Education Activist Network.
About 60 students occupied the finance department of Manchester University yesterday, demanding to see details of cuts to the university's budget. They left the building at 4.50pm after securing a meeting with the vice-chancellor. "Many of those inside were at the national demo in London," Jeremy Buck, an officer of the students' union, said. "We were very tired but still very willing to take action against these cuts to higher education."
Tory politicians alleged yesterday that NUS officials were seen encouraging the violence during the march, but the claim was immediately denied. "There is no evidence to back up accusations that NUS stewards did anything to encourage this despicable violence," Aaron Porter, the NUS president, said. "We are co-operating fully with the police and welcome their investigations into the actions of a minority that have acted shamefully and distracted from the positive actions of tens of thousands."
However, six NUS officials, including Mr Bergfeld, have signed a petition backing those arrested.
Evidence collected at Millbank after seige
Police and cleaners were hard at work at 30 Millbank yesterday, gathering evidence and clearing up the debris after Wednesday's rioting.
The Conservative Party headquarters was sealed off with police tape as officers gathered fingerprints from the foyer and other parts of the building that had been occupied by student protesters.
Outside, cleaners scrubbed "Tory pigs" graffiti from the walls and cleared up bits of broken placards, glass and bottles.
The Charity Commission, which is also based at the Millbank building, said it would not be open again until Monday.