Thousands of German police stepped in Sunday to remove anti-nuclear protesters at several points along a railway line carrying a controversial shipment of spent nuclear fuel rods from France to a storage facility in northern Germany.

The train entered Germany Saturday from a reprocessing plant in northwestern France. Ahead of the border crossing, French demonstrators launched a series of protests that have slowed the progress of the train since it left northern France last week.

The shipment of 11 waste containers is expected to arrive at its final destination — a storage facility near the northern town of Dannenberg — later Sunday or Monday.

Police near Dannenberg on Sunday were trying to free four protesters who had attached their hands to a rail track under a cement pyramid.

The annual shipment from France has been a focal point for anti-nuclear advocates in recent years, with protesters claiming the shipments are not safe.

But this is the first such shipment since German Chancellor Angela Merkel earlier this year announced moves to speed up the shutdown of all Germany's nuclear plants by 2022. Her announcement followed the nuclear disaster at Japan's Fukushima-Daiichi nuclear power plant in March.

German police on Saturday used water cannon to disperse thousands of protesters near Dannenberg.