The attack on a Christmas market in Magdeburg has raised questions about public safety and intelligence gaps in Germany. Police have described the suspect as "atypical," while experts have also blamed social media.

German authorities said they received tipoffs last year about the suspect in a car attack at a Christmas market in Magdeburg as more details emerged on Sunday about the five people killed.

Officials say four women and a 9-year-old boy were killed when a Saudi doctor drove into a Christmas market teeming with holiday shoppers in the German city of Magdeburg on Friday.