Reuters/Michael Dalder
German police secure the main train station in Munich.
German law enforcement are hunting for as many as seven people feared to have been plotting suicide bombing attacks on train stations on New Year's Eve.
Multiple stations in Munich were shut on Thursday night but have since reopened but authorities said on Friday the threat remains at a high level.
A spokesman for the German police told AFP: "We still have many colleagues deployed. There is, as before, a high threat of terror."
The BBC is reporting that police are looking for "five to seven" suspects who are believed to be of Iraqi and Syrian nationality.
Federal interior minister Thomas de Maizière defended the heightened alert in one of Germany's largest cities.
He is quoted by German newspaper Bild as saying: "The Bavarian authorities have prudently with the support of the Federal Police, level-headed and decisive action.
"In the future, the security authorities will analyse the situation thoroughly and take appropriate measures consistent."
Joachim Herrman, the interior minister for the state of Bavaria, has revealed that German authorities were notified of the threat by a "friendly intelligence service" and described it as a "concrete" tip.
Germany is among several nations involved in the air campaign against Islamic State militants in Iraq and Syria.
Security concerns saw multiple European cities cancel or alter their New Year's Eve plans.
Events in Brussels, Paris, and Moscow were also called off while in London over 3,000 police were on duty.