Authorities across Europe mounted a manhunt for those involved in a large-scale terrorist plot following the deadliest attacks to strike Spain in more than a decade: two vehicle assaults in Barcelona and the Catalan coastal town Cambrils , reports the Washington Post .
Investigators believe that at least eight people plotted the attacks, putting them at a level of sophistication comparable to major strikes in Paris and Brussels in recent years. Other more recent attacks in London, Berlin, and the southern French city of Nice were perpetrated by individuals operating largely on their own.