More than three weeks after the Cologne sex assaults, there is a security clampdown in Venice

Thousands attended the grand opening in St Mark’s Square of the Venice Carnival, celebrated under heightened security following the sexual assaults on New Year’s Eve in Cologne and the ongoing terror threat in Europe.

Authorities have increased surveillance throughout the city and increased the number of officers on patrol, both under-cover and in uniform, but rejected a proposal to ban revellers from wearing masks.