The man appears to have had an “Islamist motivation according to our current knowledge”, prosecutors told AFP.

Local media reported that the man was a 30-year-old Iraqi who had shouted “Allahu Akbar” (God is Greatest) when getting out of his car Tuesday night.

Berlin's State Security is investigating a man who caused the city highway to be closed for hours.. Photo: DPA

Three accidents occurred on the A100 city motorway at about 6.30pm in the Berlin neighbourhoods of Wilmersdorf, Schöneberg and Tempelhof, reported the Berliner Morgenpost.

A motorist rammed several vehicles, including three motorcycles, with his Opel Astra, coming to a halt at the Alboinstraße exit in Tempelhof.

He threatened the policemen with a supposedly “dangerous object” he was carrying in a box, and was arrested.

“Nobody come any closer or you will all die,” the Bild daily quoted the suspect as saying after he stopped his car and placed the metal box on the roof of his vehicle.

A spokesperson for Berlin's fire department said that three people were seriously injured, and three others lightly injured, including a motorcyclist.

The man is being investigated by Berlin's State Security. The Autobahn A100 was closed for several hours on Tuesday due to the accidents.

Because of the ongoing investigations, parts of the Autobahn were still closed on Wednesday morning, leading to rush hour traffic jams.

According to the Berliner Zeitung, police used a drone for filming from the air.

Forensic technicians x-rayed the metal box the man was carrying, and said it was suitable for storing ammunition.

However, when police opened the box using high-pressure water jets it was found to contain nothing but tools. They also did not find any explosives in the man's car.

“The possibility of an Islamist attack cannot be ruled out in view of the events of yesterday evening,” prosecutors said in a statement the day after the incidents.

“Statements by the accused suggest a religious Islamist motivation” for his
actions, they said, adding: “There are also indications of psychological instability”.

The suspect was arrested on suspicion of attempted murder in at least three cases and later today was to face a judge who will decide whether he should be placed in a psychiatric facility.

One of the injured was a firefighter, said Berlin interior minister Andreas
Geisel, adding that he was “dismayed that innocent people have fallen victim to a crime out of nowhere”.

“We must be aware that Berlin remains a focus of Islamist terrorism,” he added.

The suspect had published clues on social media that he was planning an attack, according to the DPA news agency.

He had posted photos of the car used for the attack on Facebook, along with religious slogans, the report said, citing a spokesman for the prosecution.

Previous incidents

People with ties to Islamic extremism have committed violent attacks in Germany in recent years.

The worst was a ramming attack at a Berlin Christmas market in December 2016 that killed 12. The Tunisian attacker, a failed asylum seeker, was a supporter of the Islamic State (IS) jihadist group.

More recently, an Islamist and his wife were convicted of planning a biological bomb attack in Germany in 2018 with the deadly poison ricin.

The pair had ordered castor seeds, explosives and metal ball bearings on
the internet to build the toxic bomb.

READ ALSO: Man handed 10 year jail term for biological bomb plot in Germany

The man was in March sentenced to 10 years in prison while his wife received an eight-year sentence in June.

Since 2013, the number of Islamists considered dangerous in Germany has
increased fivefold to 680, according to security services.

German Chancellor Angela Merkel has often been accused, particularly by the
far right, of having contributed to the Islamist threat by opening the country's borders to hundreds of thousands of migrants in 2015.