DANNENBERG, Germany -- Activists rappelled down from a high bridge, broke through police lines and chained themselves to German train tracks Sunday, trying to halt a shipment of nuclear waste as they protested Chancellor Angela Merkel's plans to keep using nuclear energy.
The train, which set off Friday from a reprocessing plant in France, headed toward the northern town of Dannenberg, where containers carrying 123 tons of reprocessed nuclear waste were to be loaded onto trucks for their journey to a disputed storage site at Gorleben.
Riot police tried to stop up to 4,000 protesters making their way through the woods onto the tracks near Dannenberg ahead of the train. Police used water cannons and pepper spray and wrestled with activists to break up the protest, but some still reached the rail line.
Some protesters poured flammable liquid on a police vehicle and set it alight.
Anti-nuclear protests have gained new momentum from Merkel's decision to extend the life of Germany's 17 atomic power plants by an average of 12 years.
Merkel says the move is necessary to keep energy cheap and readily available as Germany works to ramp up its renewable energy sources. Critics call the nuclear plan a windfall for Germany's biggest energy companies.
Nuclear energy has been unpopular since fallout from the 1986 Chernobyl disaster in Ukraine drifted over Germany, and the country has no plans to build new nuclear plants.
In central Germany, a pair of activists rappelled off a 250-foot-high bridge holding an anti-nuclear banner, while about 50 others crowded onto the tracks, according to federal police spokeswoman Cora Thiele.
The protest stopped the train, but police hauled the demonstrators away and the train continued on. The two protesters who rappelled from the bridge and three others were taken into custody, Thiele said.
Some 50 to 60 tractors blocked the main road between Dannenberg and Gorleben but they were cleared away by police. The roughly 12-mile (20-kilometer) road was lined with police trucks.
The train was stopped twice more by people on the tracks. In one case, police had to dislodge three protesters who had chained themselves to the line.
Authorities gave no schedule for the shipment. The train slowly made its way Sunday evening along the single-track branch line that ends at Dannenberg, but it was unclear when it would arrive. A large group of demonstrators sat on the track near the village of Harlingen.
Wolfgang Ehmke, a spokesman for a local anti-nuclear group, said blockades aimed "to delay the arrival of the shipment and at the same time mess up the timetable for the (government's) nuclear policy." He called on both sides to refrain from violence.
On Saturday, at least 25,000 people -- organizers gave the figure as more than 50,000 -- demonstrated peacefully outside Dannenberg, the biggest protest ever against the shipments.
Activists say neither the waste containers nor the Gorleben site, a temporary storage facility, are safe. The waste is stored in a warehouse near a disused salt mine that has been earmarked as a possible permanent storage site.
Protests against the regular waste shipments faded somewhat after a previous government embarked a decade ago on plans to phase nuclear power out entirely by 2021 -- but this year Merkel's government decided to extend the life of the nuclear plants. Parliament approved the plan last month.
Germany receives waste shipments roughly every year under an agreement that sees spent fuel sent to France for reprocessing and returned for storage. Safety measures for the shipment involved sealing the solid nuclear waste in glass that is in turn encased in 16-inch (40-centimeter) -thick steel containers.
Merkel calls nuclear power a "bridging technology."
Decisions such as keeping nuclear plants running "may be unpopular at the moment, but they will pay off," Merkel was quoted as telling Focus weekly. "They are necessary for us also in future to be a successful economic center."