Anti-nuclear activists worry over the safety of the warehouse in Gorleben, where the waste is to be stored while a long-term storage facility is built.

A train carrying nuclear waste was slowed down by activists on Sunday as it continued its journey to a storage site in northern Germany. The highly radioactive transport was delayed by almost two hours early on Sunday, when two activists suspended themselves over the railway tracks, forcing the train to slow down to a crawl.

Other protesters obstructed sections of track and had to be removed by police. Officers detained 16 activists overnight caught with utensils to chain themselves to the railway tracks.

Tens of thousands of protesters remained in the town of Gorleben, the final destination of the consignment. Police said 20,000 people had taken part in demonstrations there on Saturday, in the largest ever protest of its kind.

The train is carrying 123 tonnes of spent radioactive rods from German reactors, which were cooled and fused inside blocks of glass at a reprocessing plant in France.

It arrived in Germany on Saturday, where around 16,500 police officers have been assigned to protect the transport on its 600- kilometre journey to Gorleben.

Environmental organization Greenpeace warned that one of the train’s axles had become noticeably hot on Saturday, according to infrared images. Police said they discovered no anomalies when they checked the train.

Anti-nuclear activists worry over the safety of the warehouse in Gorleben, where the waste is to be stored while a long-term storage facility is built. Nuclear opponents also fear that Gorleben will effectively turn into a permanent storage site for the solid iron containers holding the nuclear waste, and have expressed doubt over government proposals to bury it 860 metres deep in a rock salt formation.

The protest is also directed at Chancellor Angela Merkel’s centre-right government, which decided to extend the life-spans of Germany’s 17 nuclear power stations by an average of 12 years beyond a previous 2022 deadline.

The decision to extend nuclear power generation was passed last week in the lower house of parliament, where Ms Merkel’s coalition has the majority.

Germany has a long history of opposition to nuclear power, dating back to the 1970s and reinforced by the 1986 nuclear disaster at the Ukrainian reactor in Chernobyl.

After at least eight hours of delay, the rail transport is expected in Dannenberg late on Sunday, where the 11 containers will be lifted onto lorries for the remainder of the journey.