PARIS - The French military fired on pirates in the Indian Ocean on Saturday to protect two tuna fishing vessels, a spokesman for France's armed forces said.

The operation at dawn some 350 km (220 miles) from the Seychelles was the first time the French had repelled an attack since a plan was put in place in July for the military to protect boats in the region from Somali pirates.

French soldiers opened fire on two small launches that were trying to approach the vessels bearing the French ensign. No one was injured on the tuna ships, which are based at Concarneau, in southern Brittany, the spokesman said. There were shots ... it lasted half an hour and at one point they turned around, the captain of one of the tuna vessels, Christophe Guyader, told France Bleu Breizh Izel radio.

France and Spain base fleets in the Seychelles and haul nearly two thirds of the year's catch off Somalia between August and November, experts say.

European fleets have said Somali pirates, which have made millions of dollars from ransoms, are threatening an industry worth up to $6 billion annually across the Indian Ocean region.

Pirates from the lawless Horn of Africa state hijacked a Spanish tuna fishing boat in the Indian Ocean earlier this month.

The French military said on Wednesday that one of its naval vessels had repelled a night assault by Somali pirates who apparently believed it was a cargo ship.

French armed forces spokesman Christophe Prazuck said pirate attacks had been decreasing, with between 10 and 15 boats on average being held last year compared with four currently.

It is still too soon to say whether this reduction is due to the actions of the international community ... or the weather. We are coming out of the monsoon season, which is not favorable toward the pirates' small boats, he added.

(Reporting by Elizabeth Pineau; editing by Philippa Fletcher)