Thousands of revelers welcome Pamplona's annual bull-running fiesta

Revellers attend the opening of the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Vincent West

PAMPLONA, Spain (Reuters) - Thousands of cheering revelers filled Pamplona's main square on Friday to watch the traditional "chupinazo" firecracker being set off, marking the start of the northern Spanish city's annual San Fermin festival.

Participants drank and sprayed sangria ahead of the opening of the festival which draws tourists from around the world for its daily bull runs in the city's narrow streets.

Wearing the traditional white T-shirts and trousers, the crowd cheered and chanted while waiting for the "chupinazo", which is in the shape of a rocket, to be fired into the sky at midday (1000 GMT). They then tied red handkerchiefs around their necks celebrating the start of the week-long fiesta.

Revellers hold up traditional red scarves during the firing of 'chupinazo" which marks the opening of the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Vincent West

The runs, during which the bulls chase runners through the streets, start each morning at 8 a.m. (0600 GMT) over a stretch of 800 meters (0.5 mile).

This year's fiesta has been preceded by a controversial court ruling in April in which five men, who called themselves "The Wolf Pack", were cleared of raping an 18-year-old woman at the 2016 event and convicted of the lesser crime of sexual abuse.

The city has made calls to reassure women they will be safe from abuse during the festival, countering calls for a boycott of the event in protest of the failed rape prosecution.

A reveller drinks wine from a shoe during the opening of the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Joseba Etxaburu

(Reporting By Reuters Television; Editing by Matthew Mpoke Bigg)

Revellers hold up traditional red scarves during the firing of 'chupinazo" which marks the opening of the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Vincent West

A reveller is thrown into air by others during the opening the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Susana Vera

Revellers celebrate while drinking and spraying sangria before the opening of the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Susana Vera

Revellers react after being splashed with water during the opening of the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Susana Vera

Revellers hold up the traditional red scarves during the firing of 'chupinazo' which opens the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Susana Vera

Revellers hold up the traditional red scarves during the firing of 'chupinazo' which opens the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Susana Vera

A revellers reacts after being splashed with water before the opening of the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Vincent West

Revellers are splashed with water before the opening of the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Susana Vera

A reveller holds up the traditional red scarf during the firing of 'chupinazo' which opens the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Susana Vera

Revellers play and celebrate before the opening of the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Susana Vera

A female reveller is seen wearing her red San Fermin scarf around her wrist before the opening of the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Susana Vera

Revellers are splashed with water before the opening of the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Joseba Etxaburu

A reveller drinks from the wineskin before the opening of the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Susana Vera

Revellers are seen before the opening of the San Fermin festival in Pamplona, Spain, July 6, 2018. REUTERS/Susana Vera