|Prince Charles and his wife were unharmed by the attack on their car [EPA]
Police and students have blamed each other for violent clashes in London over the government's decision to triple university tuition fees.
Among the incidents on Thursday, a car carrying the Prince of Wales was attacked by protesters, while one student was left with serious head injuries after allegedly being beaten by police.
Paul Stephenson, the Metropolitan police chief, on Friday pledged to launch a full and detailed investigation into the attack on the heir to the throne's Rolls Royce as it drove through London's busy West End area.
Stephenson, who declined to go into specific security operation details, said the route of the royals' car was thoroughly "reccied" in advance, but due to the "unpredictability" of protesters, this put security operations in a "very difficult position".
Thousands of students had staged a peaceful protest on Thursday, protesting against the rise in fees from about $4,700 to $14,100, but others turned violent, hurling sticks and rocks at riot police and smashing store windows.
Police said 43 protesters and 12 officers were hurt in the demonstrations, with 22 arrests made.
Susan Matthews, the mother of Alfie Meadows, a 20-year-old student at Middlesex University, said that her son had suffered bleeding to the brain after being hit by a police truncheon as he tried to leave the Westminster Abbey area.
Meadows underwent a three-hour operation and was said to be recovering in hospital.
The Independent Police Complaints Commission has started an independent investigation into the incident after it was informed by the Metropolitan police about the allegation.
Students have criticised police tactics - particularly the practice of "kettling, in which demonstrators are held in a small area for long periods of time.
Stephenson commended officers for their bravery and said the nearly 3,000-strong contingent of officers out to deal with the protests showed commendable restraint in dealing with the "dreadful" actions of "thugs".
Speaking outside Downing Street on Friday, David Cameron, the British prime minister, said: "What we saw on the streets of London yesterday was completely unacceptable.
"Of course there is a right to protest peacefully, there always should be, but there is not a right to go on the streets of London wanting to pursue violence and smashing up property."
Cameron also shrugged off claims that violence was limited to a small minority of protesters. "It wasn't," Cameron said.
"There were quite a number of people who clearly were there, wanting to pursue violence and to destroy property."
The prime minister said Stephenson was looking into a possible security breach following the attack on Prince Charles' car, which saw a group of up to 20 protesters, some chanting "off with their heads!" smashing a rear window and splashing white paint on the vehicle.
Cameron said the perpetrators should take full responsibility for their actions, adding that police should take lessons from the "regrettable" incident.
Charles and his wife were visibly shaken, but unharmed by the attack.
The incident was particularly embarrassing for police in the run-up to Prince William's 2011 wedding, raising questions over whether or not security protocols need to be reviewed.