The alleged gunman Colonna is now under arrest

The eight - all Corsicans - were sentenced to terms ranging from 15 years to life in connection with the murder of Claude Erignac.

Erignac, the prefect, or governor of Corsica, was shot three times in the head as he walked down a busy street in the island's city of Ajaccio.

Last week French police arrested the alleged gunman Yvan Colonna in southern Corsica. He had been on the run for four years.

France has vowed to crackdown on the separatist violence that has plagued the island for 30 years.

Shouts of defiance

Two of the men, Alain Ferrandi and Pierre Alessandri, were handed life sentences for the parts they played in the murder.

The reading of the verdicts was met initially met with silence then some relatives of the defendants stood up shouted and "Freedom!" while others raised their fists and began singing the Corsican national song.

French radio reported that one of the defendants shouted "Long live the struggle!" - a cry which was taken up by many others in the courtroom.

The referendum result was a bitter blow for Paris

Mr Colonna's arrest came as Corsicans went to the polls in an historic referendum to decide whether to accept a French plan that would lead to more autonomy for the island.

The 260,000 inhabitants voted by a tiny margin to reject the plan, which would have given them a new national assembly with tax-raising powers and greater control over public services.

Amid fears of a fresh upsurge of violence, four bombs exploded overnight on Sunday, destroying holiday homes belonging to French people from the mainland.

French Interior Minister Nicolas Sarkozy warned that his security forces would now get tough with separatists.

"My priority in the months to come will be to ensure the security of the island and public order," he said in a statement. "The state cannot be absent from Corsica. The days of impunity are over."

Mr Sarkozy had made eight visits to the island in the past 14 months to push for a Yes vote, and its rejection was seen as a personal blow to him.

France's President Jacques Chirac joined his interior minister in insisting that further unrest would be combated.