Two men were seriously injured during the traditional Running of the Bulls in the Spanish city of Pamplona today, one day after another runner was gored to death there for the first time since 2003, media reported.

Television showed one man being gored in the neck before he was trampled under the hooves of bulls charging through the city's narrow streets surrounded by dozens of runners trying to get as close as possible to the animals.

A 44-year-old local man was caught by a bull weighing over half a tonne, after the animal became detached from others and was circled by a crowd of runners just before end of the course at the bull ring.

The bull impaled him in the chest, before returning to toss the bloodied man into the air several times and shredding his traditional white trousers, despite efforts by other runners to distract the animal and pull it away by its tail.

"He has a very, very serious prognosis. We have to wait to see if his lung becomes infected," the doctor treating him told a news conference.

Damniel Jimeno, a 27-year-old from Alcala de Henares near Madrid, was fatally gored in the neck yesterday. His body was due to be cremated today.

Pamplona's 'San Fermin' is one of hundreds of bull-running fiestas held in Spain every year but was made famous by Ernest Hemingway's novel 'The Sun Also Rises' and the week-long fiesta now attracts hundreds of runners from around the world, often drinking all night before the early morning run.