The death toll in a car-ramming attack at a Christmas market in the German city of Magdeburg has risen to five people, and more than 200 have been injured, many of them seriously, state premier Reiner Haseloff said on Saturday.

German authorities are investigating a Saudi doctor, arrested as the suspected driver of the car, with Der Spiegel magazine reporting he had sympathies with the far-right Alternative for Germany (AfD) party.

More than 60 people were injured, some of them seriously, when a vehicle drove through crowds gathered at a market in the central city, local officials said. A young child was among the dead.

Police said they arrested a 50-year-old from Saudi Arabia who had been living in Germany for almost two decades. Police did not name the man.

The man worked as a doctor in a nearby town, local officials said. Police searched his home overnight.

A Saudi source told Reuters that Saudi Arabia had warned German authorities about the attacker after he posted extremist views on his personal X account that threatened peace and security.

The attack comes at a time of heightened debate over migration and security in Germany, which is gearing up for a snap election on February 23.

The AfD, currently polling in second place behind the conservative opposition, has led calls for a crackdown on migration to the country.

AfD chancellor candidate Alice Weidel condemned the attack and said on X, "The pictures from #Magdeburg are shocking! My thoughts are with the bereaved and injured. When will this madness come to an end?"