Thousands of peace activists demonstrated Saturday outside the Ramstein Air Base in Germany to protest the facility's reported leading role in the US drone programme.
Ramstein, which is the principal US Air Force facility in Europe, is located in a rural area of south-western Germany, near the city of Kaiserslautern.
Some 5,000 people from across Germany helped formed a human chain stretching several kilometres, organizers said.
Local police put the number of protesters at around 2,000.
Among the participants was Germany's Oskar Lafontaine, a leftist maverick and former finance minister, who called the US drone programme contrary to international law and criticized the German government's position on the issue.
"It's intolerable that the government remains silent," Lafontaine said.
He said it was "schizophrenic" that Berlin offers a generous approach to refugees but then gives its support to wars waged by the United States.
The Intercept website reported last year that Ramstein serves as the high-tech heart of Washington's drone operations in the Middle East, Afghanistan, Pakistan and Africa.
The German and US governments have repeatedly downplayed the importance of the facility and have evaded direct questions about its role in the drone programme.