Revelers run with bulls from Fuente Ymbro ranch during the first day of the running of the bulls at the San FermÌn fiestas in Pamplona, Spain.

Revelers run with bulls from Fuente Ymbro ranch during the first day of the running of the bulls at the San Fermín fiestas in Pamplona, Spain.

Revelers run with bulls from Fuente Ymbro ranch during the first day of the running of the bulls at the San Fermín fiestas in Pamplona, Spain.

A municipal music band makes its way through the crowd as revelers pack the main square during the start of nine days of uninterrupted partying in Pamplona's famed running-of-the-bulls festival in Pamplona, Spain.

Revellers cool off with water thrown from balconies during the start of nine days of uninterrupted partying in Pamplona's famed running-of-the-bulls festival in Pamplona, Spain.

Revelers pack the main square during the start of nine days of uninterrupted partying in Pamplona's famed running-of-the-bulls festival in Pamplona, Spain.

Revelers pack the main square during the start of nine days of uninterrupted partying in Pamplona's famed running-of-the-bulls festival in Pamplona, Spain.

Revelers pack the main square during the start of nine days of uninterrupted partying in Pamplona's famed running-of-the-bulls festival in Pamplona, Spain.

Revelers pack the main square during the start of nine days of uninterrupted partying in Pamplona's famed running-of-the-bulls festival in Pamplona, Spain.

Attendees wait on their balconies as rain begins to fall during the first day of the running of the bulls, at the San Fermín fiestas in Pamplona, Spain.