PAMPLONA, Spain (AP) — A traditional firework known as the "Chupinazo" kicked off Pamplona's famed San Fermin running of the bulls festival on Friday.

The bull runs are the highlight of the world-famous fiesta, but its seamless nine days and eight nights of traditional events, music and alcohol-soaked parties attract around one million visitors every year to the northern Spanish city of nearly 200,000.

Authorities have launched all kind of security measures and special protocols to prevent and deal with sexual abuse cases, which are increasingly being reported by women at festivals across Spain.

Stepped-up police surveillance and training, information booths and 24-hour hotlines are being reinforced this year with a new mobile app that allows the instant reporting of abuse, including victims' real-time locations.

The festival opened Friday at noon when a man and a woman from a local music band whose members have Down Syndrome launched a rocket from Pamplona's town hall balcony, prompting cries of joy from thousands packed in the square below.

The pair chosen for the launch this year were Leire Zabalza, 28, and Ibai Ganuza, 27, musicians of the band "Motxila 21" — or "Backpack 21," in English — named after the number of the chromosome that causes its members' genetic disorder.

Amid shouts in Basque and Spanish of "Long life to San Fermin," the saint honoured by the festival, people in the crowd wore the festival's typical red scarf and sprayed each other with wine, staining the traditional white attire.

The San Fermin festival was immortalized by American Literature Prize winner Ernest Hemingway in his 1926 novel "The Sun Also Rises," and draws around one million visitors annually.

For eight consecutive mornings starting Saturday, daredevils will race with bulls along an 850-meter (930-yard) street course to the city's bullring, where the animals are killed during the traditional corridas.

Four Americans and three Spaniards survived last year after they were gored by the bulls, while dozens other suffered injuries and bruises, mostly due to falls during the race.

Some rights activists say the events involving bulls are cruel and cause unnecessary harm to the animals for the sake of human entertainment.

But aficionados and bullfight promoters say the bull is a key part of the San Fermin tradition that needs to be preserved.

Bullfights are protected under Spain's constitution as part of the country's cultural heritage.