Summary:
Police in London have arrested a further 13 people during protests against planned tuition hikes.

Full article:
London, England (CNN) -- Police say they arrested a total of 153 people when students protested against planned hikes in university tuition. Police said that after the protest was scheduled to end Tuesday at 2 p.m., a large group of protesters still congregated at Trafalgar Square. "As a result a group of around 150-200 people who still refused to leave were contained by police in Trafalgar Square. Despite repeated requests to disperse, this group remained," London's Metropolitan Police said in a statement late Tuesday. Authorities said 139 of the 153 were arrested for breach of the peace. Others were charged with violent disorder, common assault, obstructing police and criminal damage. iReport: Student protestors demonstrate in London . The protesters say they are angry at government plans to remove the current annual cap of 3,000 pounds (about $4,700) on university tuition and allow schools to charge as much as 9,000 pounds (about $14,200). The change is part of the government's plan to cut its massive budget deficit. Defenders of the plan say universities will not necessarily charge the maximum they're allowed to, and the government has said students will not need to pay back the fees until they earn at least 21,000 pounds (about $32,600) a year. That threshold is currently 15,000 pounds (about $23,300) a year. CNN's Carol Jordan contributed to this report.