"This transport...represents a scandalous risk for the populations along the route," said Frederic Marillier, responsible for nuclear issues at Greenpeace.

The shipment has already attracted demonstrators to Gorleben, northern Germany, where it is eventually to be stored, and Greenpeace said more demonstrations were expected in the suburbs of the French border city of Strasbourg.

The convoy comprises two diesel engines followed by two wagons of security officers, the six nuclear waste containers, a police wagon and another engine, Greenpeace said.

German police, who have mobilised 15,000 officers to protect the shipment, said aircraft would be banned from flying low over the route to free airspace for their own helicopters.

"It has nothing to do in this case with terrorist attacks," a police spokeswoman said, when asked if the move was a response to the September 11 attacks in the United States, which led to security at German nuclear sites being increased.

PROTESTERS BLOCK ROADS

In Germany, farmers accompanied by some 2,000 protesters used more than 200 tractors on Sunday to block roads around Dannenberg, where the containers are due on Tuesday or Wednesday to be transferred to lorries for the final 20 km (12 miles) of their journey.

"We want to show that we are not prepared to take this sitting down, but we know that once again we will not be able to stop the containers," said farmers spokesman Hans-Werner Zachow.

On Saturday some 5,000 people in Lueneburg and another 800 in Karlsruhe marched in protest at the plans, while about 20 Greenpeace activists spent the night of Saturday to Sunday at Valognes railway station.

Security forces had to dislodge two protesters who had climbed onto the railway signals, Greenpeace said, while police said they had found a large concrete slab on the tracks, similar to ones used by demonstrators in past protests to delay trains.

Police used heat-seeking cameras on Saturday night to check along the rail route for protesters, a Reuters photographer reported.

Two weeks ago a fire in trailers under an iron bridge which lies along the route caused damage worth an estimated one million marks ($455,000).