The International Organization for Migration is urging Europe to prepare contingency plans as internal displacement in Iran threatens to spill across international borders.
Authorities are hunting suspected members of the left-wing extremist Vulkangruppe after an arson attack plunged tens of thousands of homes in Berlin into darkness for days.
More than 1,500 applicants have reapplied for asylum in Germany since border controls were tightened in May this year, despite having previously been denied entry or asylum.
