PAMPLONA, Spain (AP) — Tens of thousands of revelers showered each other with sparkling wine and waved red kerchiefs as the blast of a small rocket signaled the start of this year’s edition of the running of the bulls.

Spain’s most famous summer festival kicked off Friday in the jam-packed main square of this northern town. People from around the world, many wearing the traditional red kerchief and white shirt and pants, roared their approval as an official on a balcony at city hall declared the San Fermin festival under way. He then lit the rocket and its echo boomed through the plaza.

The first of eight runs in which daredevils dash through the streets of Pamplona with six powerful fighting bulls begins Saturday.