Security has been tightened across Germany after Al Qaeda released a new video threatening a terror attack on the country ahead of national elections.

The tape warned Germans to push their political parties to withdraw soldiers from Afghanistan or face "a rude awakening" after the polls on September 27.

ARD television and SITE, a U.S. firm that monitors militant messages, said the speaker on the video was Bekkay Harrach, who has featured in previous messages threatening Germany in the past year, Sky News reported.

"In a democracy, only the people can order its soldiers home. But if the people decides for the continuation of the war, it has delivered its own verdict," he said in the message, according to Sky News.

"The parliamentary election is the people's only opportunity to shape the policy of the country.

"With the withdrawal of the last German soldiers, the last mujaheed also will be withdrawn from Germany," he said.

Harrach called on Muslims in Germany to "stay away from anything not vital for the two weeks after the elections."

Click here for the full report from Sky News.