President Jacques Chirac on Friday condemned a rocket attack on a municipal building in Corsica amid mounting protests over plans to privatize a ferry operator that links the Mediterranean island to the French mainland.
Strikes by ferry workers and at Corsica's two main airports on Friday left the island nearly cut off from the mainland, though some flights continued to take off and land at the Ajaccio airport.
The rocket was fired at a government building in Ajaccio on Thursday evening, causing a blast felt several blocks away and damaging the building, police said.
There were no reported casualties and no one claimed responsibility.
Authorities didn't know who fired the rocket, although Interior Minister Nicolas Sarkzoy said the "unacceptable" attack would be regarded with even more gravity if it is linked to the tensions over the ferry firm, the AP reports.
He said everything would be done to find those responsible and vowed he "will not let public order in Corsica degenerate."
The strikes have grown in intensity since a dramatic airborne mission Wednesday by French police commandos who retook an SNCM vessel commandeered by striking sailors. There have also been clashes between demonstrators and riot police firing tear gas this week.
On Thursday, the government backed down from a full privatization plan and offered to keep 25 percent of the ferry operator.
Prime Minister Dominique de Villepin said he was concerned about the increasing strike action.
"I'm worried by the situation in Corsica and for Corsicans, and worried about economic development on the island," Villepin said. "They cannot multiply strikes and blockages with impunity and avoid affecting our fellow citizens who live on Corsica."