Several thousand students converged on Trafalgar Square in central London from all parts of Britain on Sunday to demonstrate against higher university tuition fees, Reuters reported. Police put their number at around 3,500. The National Union of Students (NUS) said the introduction of fees -- which mean students have to pay up to 3,000 pounds a year towards tuition costs -- had resulted in a fall in applications. The student body wants the government to reverse its policy of making undergraduates pay the top-up fees.