Spain

Most in the terrorist cell were employed or in school and showed no signs of radicalization. Their skill at avoiding detection sends chills down the spines of authorities working to prevent attacks.

Catalan separatists are arguing that Spanish police failed to keep them safe. Spain's king was booed at a vigil for victims in Barcelona. An independence referendum is scheduled for Oct. 1.

In the search for the perpetrators, Moussa Oukabir, who's reportedly 17, emerged as a key figure. He's a dual citizen of Morocco and Spain, police say.