In the wake of the deadly attacks on the Charlie Hebdo magazine and a kosher grocery store in Paris, and in an effort to foil similar incidents, French, German and Belgian authorities on Friday arrested more than two dozen terrorism suspects, The Associated Press reported.

Police are concerned about Europe's up to 5,000 radicalized Muslims, many of whom have ties to Islamic extremists in the Mideast, according to Europol. Preventing terrorist attacks has become "extremely difficult" as many Islamists have little command structures and are increasingly sophisticated, said Rob Wainwright, the head of the international police agency.

French and German authorities arrested at least 14 individuals suspected of links to ISIS, the group that controls large swaths of land in Syria and Iraq and has dubbed itself the "Islamic State." In Belgium, 13 people were detained after a Thursday raid ended in the exchange of gunfire in the eastern city of Verviers. Two suspected terrorists were killed, and a third was wounded when authorities moved on what they say was a militant hideout.

Belgian investigators spoke of a plot to murder police officers across the country, according to Reuters. Overall, authorities in the Central European country conducted more than a dozen terror sweeps, and Prime Minister Charles Michel urged people not to panic.

Five percent of the nation's population is Muslim, and local authorities believe some 300 Belgian citizens have been involved in the Syrian civil war between ISIS and forces loyal to dictator Bashar al-Assad -- the highest per-capita rate in Europe.

In Germany, police arrested two suspected Islamists in Berlin just hours after they nabbed a member of a suspected 50-member jihadi cell in the northern city of Wolfsburg, the Telegraph reported.

A bomb scare at the Gare de l'Est, meanwhile, further heightened terror fears across the continent. The Paris train station was evacuated on Friday, but no explosive device was found.

France was further rattled by another hostage situation at a post office in a town northwest of the capital. Police determined, however, the perpetrator had mental issues and no links to terrorism. No one was harmed in the incident, according to CNN.