LONDON (AP) _ About 2,000 students demanding the government keep its loan program broke away from a larger protest Thursday and scuffled with police near Parliament. About 23 people were hurt, said hospital and police sources.

The disturbances forced police temporarily to close four of the busiest Thames River bridges at Lambeth, Westminster, Waterloo and Southwark.

Protesters said the police, some of whom were mounted, charged the students. Police denied it. They reported arresting about 60 students.

The students involved set out to march on Parliament from a nearby protest of about 15,000 people, said a spokesman for the National Union of Students. The protest organizer, speaking on condition of anonymity, said they were chanting slogans at Westminster Bridge, next to Parliament, when police moved in.

''More than 20 police horses and at least 100 policemen on foot just charged a crowd of people indiscriminately. The horses went among the crowd and pushed people up against walls,'' he said.

Ali Kayley, a 21-year-old student, said a policeman hit her in the stomach and a horse trampled her. ''There wasn't any violence until the police started it,'' she said.

Press Association, the British domestic news agency, also reported that police had charged.

However, Scotland Yard denied it. It said horses are used only to control crowds and disperse people without causing injuries.

Chief Inspector Tony Johnson said students ignored orders from their own leaders to disperse and repeatedly shoved police lines.

''People are not allowed to march on Parliament,'' he said. Demonstrations are illegal at Parliament when it is in session.

Officials at St. Thomas Hospital said about 20 people, mostly students, were treated for minor hurts. Police said three officers were slightly injured.

The protesters were demonstrating against government proposals to make students take out bank loans for higher education instead of receiving government grants.