Police have arrested at least 18 people along the Royal Wedding route, Sky News reports.
The alleged offenses committed by those arrested included breach of the peace, assault, handling stolen goods and possession of an offensive weapon.
The arrests came as police and the military faced the threat of terrorists, anarchists and stalkers. A total of 21 suspected anarchists had been banned from Westminster Abbey for the historic event, Sky News reports.
As precaution, a fence of steel winds around Westminster Abbey, where thousands of well-wishers gathered to catch a glimpse of the happy couple. Armed police and undercover squads of special forces are mingling with the crowds to combat any attempt to disrupt the event.
Marksmen took up position on roofs along the ceremonial route as search teams and sniffer dogs carried out a final check of vulnerable locations. More than 80 VIP guests were given close protection bodyguards.
Police insisted they had no intelligence of a specific terrorism threat, although the U.K. remains on the second-highest alert to an attack from Al Qaeda and a substantial risk of a strike from dissident Irish republicans. Scotland Yard officials had warned they would launch a preemptive strike against any suspected troublemakers.