By Frederik Pleitgen, Margot Haddad and Steve Almasy

Two train stations in Munich, Germany, were evacuated and train service stopped on New Year's Eve, a spokesman for the Munich police said, citing concerns of a possible terror plot.

Police have received "concrete information that strongly indicates that there are possible plans for terror attacks in Munich, specifically against the main train station and the railway station in (the western district of) Pasing."

Munich police said officials had deemed the information about the threat of an attack on New Year's Eve as serious and credible.

Authorities told the public additional officers were being called in to find possible suspects.

German media reported Friday morning that Munich police said an unspecified Islamic extremist group is suspected to be behind the plans, which were to attack multiple targets in Munich.

Police are also asking the public to stay away from large gatherings.

Europe has been on edge since the November 13 terrorist attacks in Paris that killed at least 130 people. Recent weeks have brought arrests of suspected terrorists in Belgium, France, Austria and other nations.

CNN's Stefan Simons contributed to this report.

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