Thousands of revellers crammed into the main square and adjacent narrow streets of northern Pamplona today for the start of Spain’s famed San Fermin running of the bulls festival – a potent mix of adrenaline and alcohol-fuelled celebrations that span over a week.

An Irishman is in a serious condition in hospital after suffering “traumatic asphyxia” during Spain’s San Fermin bull run, according to Spanish media reports.

Charging bulls tossed, gored and terrified human daredevils today as this year’s San Fermin festival served up its longest and most dangerous run yet, with at least four people gored.