Tens of thousands of people have packed the town hall square in the northern Spanish city of Pamplona to celebrate the traditional firework blast that starts the San Fermin bull-running festival.

Nearly everyone, including many tourists, was dressed in the traditional clothes of white trousers and shirt with red sash and neckerchief as they sang and shouted.

As the rocket was fired, many doused each other with red or sparkling wine.

A band plays in the town hall square
A band plays in the town hall square (Alvaro Barrientos/AP)

Spectators watch from balconies and wooden barricades set up along the course. The spectacle is televised nationally.

The rest of each day is for eating, drinking, dancing and cultural entertainment.

Spain Running of the Bulls
Most people wore white and red clothes as they packed the square in Pamplona (Alvaro Barrientos/AP)

The bulls used in the runs are killed by professional matadors in bullfights each afternoon in the city ring.