Separating three protesters from a German railtrack was slow work Saturday for a team of police after the anti-nuclear activists used an ingenious method to lock themselves in place.

During the morning, the two men and a woman fixed their hands and arms inside tubes inside a huge lump of concrete under the track, according to fellow protesters.

A trainload of nuclear waste was unable to pass along the line. Obstructing tracks is one way the anti-nuclear movement shows its opposition to the transport of waste.

After nightfall, police said they had drilled away enough of the concrete to detach one protester's bonds at the small border town of Berg. Police said they had to be careful not to harm the protesters.

The waste train was meanwhile waiting nearby at Lauterbourg, France, at least four hours late.

A federal police spokesman said the removal of one protester's bonds enabled police to understand how the other two had secured themselves. This raised the chances the blockade could be broken within a few more hours.