The European country saw mass migration in 2015 at the height of the migrant crisis, accepting an excess of one million people.
Berlin, Ansbach, Cologne, Reutlingen, Munich, Wurzburg and Grafing have all witnessed attacks in the past 12 months.
Stephan Kramer, the regional chief of state protection and counterterrorism in Thuringia, a state in east-central Germany, said radical Islam was rife and represented a growing threat to Germany.
He said: “We receive information on terror suspects every day.”
Mr Kramer referred to the case of Dschaber al-Bakr, a 22-year-old Syrian who was later arrested on suspicion of plotting an Islamic State (ISIS) inspired attack.
He eluded the authorities in October, prompting an independent investigation into cooperation and information sharing among German intelligence.
Al-Bakr later committed suicide in a Leipzig jail.
Mr Kramer said: “We have similar information in Thuringia, too.
“I know from my colleagues in other eastern Germany states that the situation is similar there too. It’s a country-wide issue.”