Berlin, Germany (CNN) -- U.S. officials extended a travel alert in Germany and urged Americans to remain wary after terrorist organization al Qaeda posted messages in recent months threatening attacks in the country.
The alert issued Thursday will remain in effect until February 10. It replaces one issued in September that expired Wednesday, a news statement said.
It urged Americans in Germany to keep up with news reports and to consider the security procedures in place when they visit hotels, restaurants, and other entertainment and recreation venues.
"Over the past few months, al Qaeda has released videos threatening to conduct terrorist attacks against German interests," the statement said. "While these threats initially mentioned the German federal elections in September, al Qaeda continues to threaten Germany."
Germany is investigating all threats, the U.S. State Department said.
The German interior ministry said in September that it had noted an increase in threats by al Qaeda and other Islamist groups since the beginning of the year.
Al Qaeda posted a video threat online on September 18, vowing attacks if federal elections in Germany on September 27 didn't go its way.
The speaker in the video repeatedly criticized German Chancellor Angela Merkel -- who was re-elected -- and her support of the Iraq and Afghanistan wars.