The officials said Riyadh warned the German authorities the suspected attacker, Taleb al-Abdulmohsen, a Saudi dissident who described himself as an ex-Muslim, had boasted on social media that “something big will happen in Germany”. It was unclear if police ever acted upon the warnings.

Saudi Arabia had warned Germany about the man suspected of carrying out the incident at the Magdeburg Christmas market, according to Saudi Arabian security sources. Saudi Arabia requested the extradition of the suspect,