PARIS - Nearly half of Air France's flights have been grounded by a pilots' strike expected to last through the weekend.

The airline says that half its short- and medium-haul flights were cancelled along with 40 per cent of its long-haul flights.

Some flights were cancelled at the last minute.

Only Air France flights have been affected by the walkout, which is expected to last until Monday.

Pilots are protesting a plan to push the retirement age for some pilots from the current 60 to 65 starting in 2010.

Legislators in the lower house of parliament adopted the change Nov. 1 as an amendment to the Social Security finance law. While extending the work years until 65 is to be voluntary, the measure stipulates that one of the pilots on each flight should be over 60.

The railway authority announced additional cars will be added to its fast trains to cities around France to help stranded travellers reach their destinations.