BERLIN (AP) — German police officers cleared a sit-in of thousands of protesters trying to block a train carrying nuclear waste and temporarily detained 1,300 people on Sunday, officials said.

Hundreds of officers started removing protesters from the rails near Dannenberg in northern Germany in the morning, said a police spokesman, Stefan Kühm-Stoltz. Those who resisted were detained at the site for several hours, but all were released by late afternoon.

The police put the number of protesters at 3,500, while organizers said 5,000 people had occupied the tracks, the final stretch for the train. Trucks were to take the shipment, which was reprocessed in France, the remaining 12 miles to a storage site in the town of Gorleben.

Activists say the waste containers and the temporary storage site are not safe.

The police also clashed with two groups of protesters who hurled stones and fireworks.