TORDESILLAS, Spain (AFP) - Men chased and lanced to death a 650kg bull at a controversial fiesta in Spain on Tuesday, some scuffling with animal rights protesters who rallied nearby.

In the Toro de la Vega bull-run in Tordesillas, crowds on foot and horseback chased the bull for 20 minutes through the northern-central town and into a meadow.

One young man finally speared to death the bull, named Rompesuelas, and paraded with its tail tied to his lance.

Police kept apart angry participants and animal rights protesters who gathered near the bull-run route.

Minor scuffles broke out and some supporters of the bull-run struck reporters covering the event, an AFP photographer at the scene said.

The annual fiesta dates back to medieval times - a dustier, bloodier affair than the bull-runs in the northern town of Pamplona in July that are popular with foreign tourists.

Animal rights group Pacma called Toro de la Vega an "icon of animal cruelty" in Spain.

It said 120,000 people had signed a petition launched last week to ban the event.

Pacma sent the petition to the leader of Spain's opposition Socialist Party, Pedro Sanchez, asking him to put pressure on the Socialist mayor of Tordesillas to end the event.

ANIMAL CRUELTY LAW PROPOSED

In Madrid on Tuesday, the Socialists' parliamentary spokesman Antonio Hernandez said the party would table a law to ban the event.

"Pedro Sanchez will propose a law against animal cruelty so that this will be the last bull to be lanced in the meadow of Tordesillas," he told reporters.

Senior members of the ruling conservative Popular Party defends the event.

"It is a historical and cultural tradition," said Justice Minister Rafael Catala.

"It is not banned in a democratic society, a society of law. It is one of the freedoms of citizens," he told reporters.

The Popular Party currently controls parliament, though that could change in December's general election.

Spain has countless local folk festivals involving animals, but some have been called into question by left-wing councils that took power in various towns in local elections in May.

Defenders of the Toro de la Vega event on Tuesday raised a banner reading: "I have the right to my fiesta."

"It is not savagery, nothing of the kind. It is a contest between the person and the animal," said Maria Jesus Barragan, 52, a local hotel cleaner.

"The animal is stronger but the person has the intelligence."