Police in Belgium have broken up a plot to free a terrorist from prison who was convicted of planning a suicide car bomb attack at an American Air Force base:

Prime Minister Guy Verhofstadt said the government had information suggesting "preparation of an attack."

"Other acts of violence are not to be excluded," he said.

The prisoner, Nizar Trabelsi, a 37-year-old Tunisian who played soccer for several German teams, was sentenced to the maximum 10 years in prison four years ago. He had admitted planning to drive a car bomb into the canteen at Kleine Brogel, a Belgian air base where about 100 American military personnel are stationed.

The base is home to Belgian F-16 warplanes equipped with nuclear weapons that are under U.S. control, according GlobalSecurity.org, a U.S.-based military affairs think tank.

Trabelsi, who testified that he intended kill U.S. soldiers, says he met Osama bin Laden in Afghanistan and asked to become a suicide bomber. He was arrested in Brussels on Sept. 13, 2001. Police later discovered the raw materials for a huge bomb in the back of a Brussels restaurant.

The federal prosecutor's office said the 14 were planning to free the terrorist by force. "Trabelsi would be helped by a group of people, driven by an extremist vision of Islam," the prosecutor's office said.