Spain's best-known bull-running festival held in the northern city of Pamplona will be cancelled for the second year in a row because of the coronavirus pandemic, Pamplona's mayor said Monday.

"It is with regret that I am forced to officially cancel the San Fermin festival for this year 2021", Enrique Maya told a news conference.

He said staging the festival, normally held in July and which includes the hair-raising daily bull runs, would be "a very high risk" as the number of people vaccinated is still too low.

The Navarre region, the capital of which is Pamplona, has one of the highest rates of COVID-19 in Spain.

The regional authorities had already said in February that the festival would likely have to be cancelled for a second consecutive year.

The festival, in honour of the patron saint of Spain's northern Navarre region – San Fermin – dates back to medieval times and involves religious processions, concerts and all-night partying in addition to the bull runs that have made it famous.

The festival draws tourists from around the world and its cancellation will deal another blow to the local economy, already reeling from restrictions to contain the spread of the virus.