File picture.

World - German authorities are investigating why a Syrian man stole a lorry in western Germany and rammed it into several cars, with the question of whether he might have had a terrorist motive still unanswered.

"Even if the sequence of events recalls the terrible attacks in Nice or Berlin, the motive of the arrested man remains unclear," Peter Beuth, the interior minister for the state of Hesse, said on Tuesday.

The 32-year-old suspect had no links to potentially violent Islamists, based on what investigators have found so far. The federal prosecutor's office responsible for terrorist cases has not taken charge of the case.

The incident on Monday evening in the town of Limburg left eight people and the suspect slightly injured.

The man arrived in Germany in 2015 and was granted subsidiary protection the following year - a status given to people who do not qualify as refugees, but are at risk of serious harm if they return to their home country.

He had come to the police's attention with drug and violent crimes, according to information obtained by dpa. There were no confirmed indications that the man had consumed drugs or alcohol before taking the lorry, said senior public prosecutor Alexander Badle said.

Police in the state of North Rhine Westphalia had became aware of the man at the end of August, when he had harassed a 16-year-old girl at a fair in the city of Moers and got into a fight with her mother.

The man was charged with assault and battery as a result. It's unclear why he was in Moers; he lived in Langen, about a three-hour drive away.

His residence permit had expired on October 1, but it was unclear whether he had applied for an extension.

The suspect has not yet made any statement to police.

Authorities are investigating in all directions, according to the Frankfurt prosecutor's office. The man is suspected of attempted homicide, aggravated assault and dangerous traffic interference, according to Alexander Badle said.

A detention order was issued for the man on Tuesday night.

Asked whether there were any indications of a terrorist attack, German Interior Minister Horst Seehofer told journalists at an EU meeting in Luxembourg that investigations are ongoing and said: "I cannot tell you at this time how the act should be qualified."

Police accompanied by a SWAT unit searched the suspect's flat in Langen overnight to Tuesday, Badle said. The town is about 80 kilometres away from Limburg.

A relative's flat was also searched in the district of Limburg-Weilburg, prosecutors said. Mobile phones and USB sticks were seized. The relative is a cousin of the suspect, investigative sources said.

According to Badle, the suspect had stayed with the relative before Monday's incident. The relative also was near the location of the car ramming on Monday.

The suspect violently pulled the actual driver of the lorry out of its cab, according to prosecutors. He then drove a few metres with the lorry before slamming without braking into the vehicles in front of him near an intersection.

Federal police officers who happened to be nearby in their free time arrested the Syrian and handed him over to police. He had resisted arrest, dpa learned, leaving officers with slight injuries.

Seehofer praised the officers' actions, saying the rapid arrest made it possible for security authorities to clarify details of the incident.

The lorry's actual driver told the Frankfurter Neue Presse newspaper that the suspect had dragged him out of the heavy goods vehicle after he stopped at a red light.

He said the man yanked open the driver's door and stared at him with wide eyes.

"'What do you want from me?'" the driver said he asked the man. "But he did not say a word. I asked him again. Then he dragged me out of the lorry."

The logistics company Pfenning, which owns the vehicle, said on its website that it had been carrying out a delivery.

The newspaper reported that the suspect received first aid from bystanders after the collision. According to them, he said "Allah" several times.

The mayor of Limburg told dpa that he was shocked by the incident and expressed condolences. There's no such thing as 100 per cent safety, and "no one is immune to individual perpetrators," said Marius Hahn.

The incident recalled other attacks involving hijacked trucks.

One was used in December 2016 to plough into a Christmas market in the German capital Berlin, in an Islamist attack that killed 12 people and injured more than 70. In July 2016, 86 people died in a truck attack in Nice.

IOL