British police involved in the huge security operation for the royal wedding made 56 arrests for mostly minor offences in London.
Some 5,000 officers were on duty to control the huge flag-waving crowds alongside 1,000 soldiers lining the route from Westminster Abbey to Buckingham Palace on Friday.
Specialist teams with sniffer dogs had patrolled the procession route searching for explosives, while helicopters buzzed overhead as part of the operation to protect Prince William and his new wife Kate Middleton.
By 1615 GMT, a Metropolitan Police spokesman said there had been 56 arrests, Reuters reported. Most of those detained were held for minor public order offences.
Police arrested 10 people at Charing Cross railway station after they were found to be carrying anti-royalist placards.
Police said they monitoring small groups of protesters in central London.
A handful of protesters gathered in Trafalgar Square, where crowds were watching the proceedings on a giant screen, and displayed a banner complaining about government cuts to public services and Britain's military role overseas.
Earlier, three two men aged 45 and 68 and a woman of 60 were detained in southeast London on suspicion of conspiracy to cause a public nuisance and breach of the peace. They were suspected of planning to behead royal effigies.
A fourth person, described by police as "a well-known anarchist", was arrested in Cambridge, northeast of London.
A lawyer representing some of those arrested said that police had abused their power by using security concerns as a pretext to block protests that could embarrass the royal family.
The London force was criticised for its handling of student protests last year when demonstrators attacked a car carrying Prince Charles and his wife Camilla Duchess of Cornwall.
Police were prepared for a wide range of possible threats, from militant Irish republicans to Islamist groups, anarchists and stalkers.