The accidents occurred on the A100 highway in Germany's capital.
CNN  — 

Police in Germany have arrested a 30-year-old man whom they say caused a series of motorway incidents in Berlin, in what prosecutors say is a “suspected Islamist act.”

Six people were injured, three seriously, in Tuesday evening’s crashes, which appeared to be targeted mainly at motorcyclists on the A100 in the German capital.

Shortly before 7 p.m. (1 p.m. ET) Tuesday “several collisions occurred on the Federal Motorway 100, which, according to initial investigations, are related and must be considered intentional attacks on other road users,” read a joint statement from the Berlin police and the Berlin Public Prosecutor General’s Office on Wednesday.

Prosecutors described the incident as a "suspected Islamist act."

“The possibility of an Islamist attack cannot be ruled out in view of the events of yesterday evening … between Wilmersdorf and Tempelhof,” according to the prosecutor’s office. It added that statements made by the suspect suggested “a religious Islamist motivation” with “indications of psychological instability.”

After the suspect’s car was stopped following a collision with another vehicle he placed an old ammunition box on the roof of his car, giving the impression that it could be a dangerous object, according to the statement.

The suspect showed "indications of psychological instability," according to the prosecutor's office.

Specialists from the State Criminal Police Office secured the contents, which turned out to be a number of tools, after opening the container.

The suspect was taken into police custody and questioned, with investigations taken over by the State Police Department of the State Criminal Police Office. Police have “so far been unable to find any evidence of membership of a terrorist organization,” according to the statement.

Investigations are ongoing and the suspect is expected to be brought before a judge on attempted murder charges later on Wednesday.