Germany remained on alert after the release of the fourth al-Qaida message in a week, with Osama bin Laden issuing a warning to Europe and others calling on Muslims in Germany to take part in jihad, or holy war, authorities said Friday.
Bin Laden issued a new audio message warning of retaliation against Europe for its alliance with the U.S. in Afghanistan, the U.S.-based SITE monitoring service said on Friday.
The al-Qaida leader denounced NATO airstrikes in Afghanistan that have killed civilians and warned that European countries would be held accountable alongside the Americans unless they pull out.
"A wise person would not waste his sons and money for a gang of criminals in Washington ... In summary, we are not asking too much or an invalid demand, but it would be be fair that you lift your opression and withdraw your troops," bin Laden said, addressing the Europeans.
Bin Laden's last message was addressed to the American people and was posted a few days after the eighth anniversary of the Sept 11, 2001, attacks.
Latest video to Germans
In the trio of messages addressed specifically to Germany, the last video showed a masked person presumed to be Bekkay Harrach, who uses the pseudonym Abu Talha, speaks about piety and service to Allah.
German authorities and international intelligence groups said they believe all three German-language videos were made by Harrach, a German of Moroccan background believed to have lived for years in Bonn. Authorities say he could now be in the Pakistan-Afghanistan border area.
"We are taking this seriously," German Interior Ministry spokesman Stefan Paris told reporters. He said the still image with an audio message released Thursday was not seen as increasing the existing terror threat facing Germany, which holds parliamentary elections Sunday.
The person in the third video says the best way for a "sinful Muslim seeking redemption ... is participation in jihad," according to the SITE Intelligence Group, which analyzed the video. No specific threats were mentioned.
The first video came out a week ago with a threat linked to German troops' presence in Afghanistan and the election — prompting authorities to step-up security at airports and train stations.
The second al-Qaida message mentioned Afghanistan and the issue of sin in Islam.
Germany's interior ministry said last week that the first video underlines the fact that Sunday's elections offer "a particular background for propaganda and operational actions by terrorist groups."
However, the government has tried to calm down citizens, saying there was no specific terror threat in Germany.
Chancellor Angela Merkel has said German security authorities are prepared to protect the country against potential terrorist threats.
In the U.S., on the other hand, the State Department on Wednesday issued a Travel Alert cautioning Americans to be particularly careful in coming weeks in Germany.
"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" in Germany, the alert said. It expires on Nov. 11.
The Associated Press and Reuters contributed to this report.