Five people were killed and over 200 were injured when a car was driven through crowds at the Christmas market in Magdeburg in eastern Germany. The far-right Alternative for Germany held a rally in the city on Monday.

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.

There is no question that the German authorities, both federal and state, have made some serious errors of omission in the case of al-Abdulmohsen. Whatever their reasons for not responding, as the Saudis claim, to the repeated warnings about his extremism, he was seemingly a danger to his adopted host country.