STUTTGART, Germany — The U.S. State Department is urging Americans to exercise caution during their travels around Germany in the coming weeks following a series of threatening messages by al-Qaida.

The travel alert, which advises U.S. citizens to keep a low profile, will remain in effect two weeks after Germany’s federal elections on Sunday.

Americans are advised to monitor news reports and consider the level of security present when visiting public places or choosing hotels, restaurants, and entertainment and recreation venues.

The threat, posted on the Internet by al-Qaida last week, warns Germans that the prospect of an attack hinges on the outcome of the election.

“German authorities are taking the threat seriously and have taken measures to enhance the level of security throughout the country,” the travel alert states.

Political parties in Germany are divided over the country’s involvement in Afghanistan and the role of its 4,200 troops deployed there. Though the conflict is deeply unpopular in Germany, few politicians are calling for an immediate withdrawal.

The State Department advisory calls on Americans to maintain “a heightened situational awareness” during visits to public places and consider the amount of security present.

The warning also advises citizens to monitor news reports for the latest information.