- Islamist terrorists in Belgium tied to ISIS-linked cells in Europe, source says
- Belgium says it targeted a terror cell that was plotting to attack police officers
- Paris prosecutor's office says at least a dozen suspects were detained
- Two men have been arrested in Berlin on suspicion of links to ISIS, police say
(CNN)European counterterrorism agencies scrambled Friday to assess the potential danger of a complex and growing terrorism threat exposed by the arrests of more than two dozen people with suspected links to Islamic extremists.