The Foreign Office said a video message – claimed to have been made by al Qaida – had been released urging Germans not to re-elect its government and to remove its troops from Afghanistan.
Security in Germany has been stepped up ahead of national elections taking place on Sunday.
”There is a general threat from terrorism in Germany,” the Foreign Office said.
”Such attacks could be indiscriminate, including in public places frequented by expatriates and foreign travellers.”
The guidance, posted on the Foreign Office website on Thursday, added: “The German government has taken measures to enhance security throughout the country in the run-up to the national elections taking place on September 27.
“On September 18, a video was released claiming to be from al Qaida, warning the German people against re-electing the current government and not removing its troops from Afghanistan.”
Similar advice was also issued by the United States government.
“The Department of State alerts US citizens that al Qaida has threatened it will conduct terrorist attacks in Germany immediately prior to and following the federal elections on September 27,” it said.
“This travel alert expires on November 11.”