Germans are mourning a violent attack and their shaken sense of security after a Saudi doctor intentionally drove a black BMW into a Christmas market teeming with holiday shoppers, killing at least four people, including a small child, and injuring scores of others.

The driver was arrested at the scene shortly after the car barrelled into the market at around 7pm, when it was teeming with holiday shoppers looking forward to the weekend.

Verified bystander footage showed the suspect's arrest on a walkway in the middle of the road. A nearby police officer pointing a handgun at the man shouted at him as he lay prone. Other officers soon arrived to take the man into custody.

Several German media outlets identified the man as 'Taleb A', withholding his last name in line with privacy laws, and reported that he was a specialist in psychiatry and psychotherapy.

A Saudi source said 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.

Two people were confirmed dead, an adult and a toddler, immediately after the attack, with another two confirmed later.

A report from German newspaper Bild said 41 people were critically injured, 86 were receiving hospital treatment for serious injuries and another 78 sustained minor injuries.

There were still no answers as to what caused him to drive into a crowd in the eastern German city of Magdeburg.

The violence shocked the city, bringing its mayor to the verge of tears and marring a festive event that's part of a centuries-old German tradition. It also prompted several other German towns to cancel their weekend Christmas markets as a precaution and out of solidarity with Magdeburg's loss.

The suspect is a 50-year-old Saudi doctor who moved to Germany in 2006, Tamara Zieschang, the interior minister for the state of Saxony-Anhalt, said at a news conference. He has been practicing medicine in Bernburg, about 40 km south of Magdeburg, she said.

"As things stand, he is a lone perpetrator, so that as far as we know there is no further danger to the city," Saxony-Anhalt's governor, Reiner Haseloff, told reporters.

"Every human life that has fallen victim to this attack is a terrible tragedy and one human life too many."

Describing himself as a former Muslim, the suspect shared dozens of tweets and retweets daily focusing on anti-Islam themes, criticizing the religion and congratulating Muslims who left the faith.

He also accused German authorities of failing to do enough to combat what he said was the “Islamism of Europe.” Some described him as an activist who helped Saudi women flee their homeland. He has also voiced support for the far-right and anti-immigrant Alternative for Germany (AfD) party.

Germany's FAZ newspaper said it interviewed the suspect in 2019, describing him as an anti-Islam activist.

"People like me, who have an Islamic background but are no longer believers, are met with neither understanding nor tolerance by Muslims here," he was quoted as saying. "I am history's most aggressive critic of Islam. If you don't believe me, ask the Arabs."

The violence occurred in Magdeburg, a city of about 240,000 people west of Berlin that serves as Saxony-Anhalt's capital.

Friday's attack came eight years after an Islamic extremist drove a truck into crowded Christmas market in Berlin, killing 13 people and injuring many others. The attacker was killed days later in a shootout in Italy.

Police apprehend the man who crashed his BMW into a crowd of people at a Christmas market in Magdeburg, Germany. – AP

Christmas markets are a huge part of German culture as an annual holiday tradition cherished since the Middle Ages and successfully exported to much of the Western world. In Berlin alone, more than 100 markets opened late last month and brought the smells of mulled wine, roasted almonds and bratwurst to the capital. Other markets abound across the country.

Andrea Reis, who had been at the market on Friday, returned on Saturday with her daughter Julia to lay a candle by the church overlooking the site. She said that had it not been for a matter of moments, they may have been in the car's path.

"I said, 'let's go and get a sausage', but my daughter said 'no let's keep walking around'. If we'd stayed where we were we'd have been in the car's path," she said.

German Interior Minister Nancy Faeser said late last month that there were no concrete indications of a danger to Christmas markets this year, but that it was wise to be vigilant.

Hours after Friday's tragedy, the wail of sirens clashed with the market's festive ornaments, stars and leafy garlands.

Magdeburg resident Dorin Steffen said she was at a concert in a nearby church when she heard the sirens. The cacophony was so loud "you had to assume that something terrible had happened."

Emergency services and police inspect the scene the morning after the Christmas market attack  in Magdeburg, Germany. –  Reuters

She called the attack "a dark day" for the city.

"We are shaking," Steffen said. "Full of sympathy for the relatives, also in the hope that nothing has happened to our relatives, friends and acquaintances."

The attack reverberated far beyond Magdeburg, with Haseloff calling it a catastrophe for the city, state and country. He said flags would be lowered to half-staff in Saxony-Anhalt and that the federal government planned to do the same.

"It is really one of the worst things one can imagine, particularly in connection with what a Christmas market should bring," the governor said.

German Chancellor Olaf Scholz visited the market the morning following the attack, paying tribute to the victims by laying flowers at the scene.

'Awful crime': German Chancellor Scholz visiting the Magdeburg Christmas market to lay a wreath in tribute to the victims. - Reuters

German President Frank-Walter Steinmeier said the attack interrupted the anticipation of a peaceful Christmas.

Chancellor OIaf Scholz posted on X: "My thoughts are with the victims and their relatives. We stand beside them and beside the people of Magdeburg."

NATO's secretary-general, the European Commission's president and US Vice President-elect JD Vance also expressed their condolences on X.

"Our prayers go to the people affected by this terrible attack on a Christmas market in Germany," Vance wrote.

"What a ghastly attack so close to Christmas."

Saudi Arabia's foreign ministry also condemned the attack on X but did not mention the suspect's connection to the kingdom.

Magdeburg Mayor Simone Borris, who was on the verge of tears, said officials plan to arrange a memorial at the city's cathedral on Saturday.

After a soccer match Friday evening between Bayern Munich and Leipzig, Bayern CEO Jan-Christian Dreesen asked fans at the club's stadium to observe a minute of silence.