Chains and concrete are popular campaign tools for protesters

Small numbers of people in northern Germany fastened themselves to railtracks with concrete or steel chains, forcing a train carrying spent fuel to reverse.

The protesters are a mixture of local people, German environmentalists and protesters of about 15 nationalities.

They are mainly young, but they have a lot of public support in Germany.

"Thirty years ago I was protesting against nuclear missiles in East Germany," said one pensioner in the town of Dannenberg, near to where the train was delayed on Tuesday night.

"I understand these youngsters," she said. "I don't want atomic power, either.

"But my bones are too old to sit on the tracks."

Protesters' tactics

The nuclear fuel debate has been a key political issue in Germany for more than two decades. More than a third of the country's electricity comes from its 19 nuclear reactors, which generate hundreds of tonnes of radioactive waste a year.

Our generation doesn't want nuclear power

Alex, protester

But the Berlin newspaper Tagezeitung said in an editorial on Wednesday that the German public was less fired up on the subject of nuclear fuel than even a few years ago. At the last big nuclear shipment protest, 30,000 people demonstrated, compared to just a few thousand this time, the paper said.

However, those involved in the demonstrations say they still have the backing of the local community, and have shown fierce determination.

The protesters have been blocking the tracks any way they can

Greenpeace protesters chained themselves to train tracks near Dannenberg, using a complex mass of chains and heavy locks laced beneath the rails.

Other activists, one a 16-year-old girl, locked themselves in using concrete.

A Greenpeace spokesman at the scene, Sven Teske, told BBC News Online:

"We have great respect for the peaceful demonstration of these people.

"It's minus seven degrees here and they were sitting on the tracks for 10 hours."

You'll always have some people who want to be aggressive

Sven Teske, Greenpeace

Another protester, 20-year-old Alex, from Hamburg, said the demonstrators' plan was to delay the train for as long as possible, making it so expensive for the government that it would shut the country's nuclear reactors down immediately, rather than within 25 years as pledged.

"This is our parents' garbage," he said. "Our generation doesn't want nuclear power."

The protesters have focussed on non-confrontational tactics, according to Independent Media Centre (IMC), an international network of media groups that covers grassroots protests like this one. Earlier in the week, protesters were reported to be playing youth volleyball on the train tracks.

Demonstrators have also been using tree branches to block the line.

German newspaper reports have remarked that the protests have largely been professional on both sides, with the police using mediators to talk to protesters, rather than immediately turning to tear gas.

Atmosphere

However, the protests turned violent on Tuesday night and Wednesday with protesters throwing stones and flares, and police responding with water cannon and baton charges.

There have been clashes between police and protesters

"The police are sometimes pretty aggressive," said Mr Teske. "We've messed up their time schedule."

But he stressed that the atmosphere was mostly friendly. On Tuesday night, police officers covered shivering activists with blankets and handed out helmets to protect them against the bitter cold.

"The police have their own opinions, but they have a job to do and most are not aggressive," said Mr Teske. "Most of them are quite friendly but you have to remember that many of them are quite frightened.

"When you are faced with all these people you don't feel good."

The Greenpeace spokesman also said most protesters were committed to peaceful tactics.

"You'll always have some people who want to be aggressive," he said. "But 99% of protesters are peaceful."