Police on Twitter urged citizens to stay indoors as the area was put under lockdown, with rail company Deutsche Bahn announcing that the city’s main station was shut down.
A high school in the area was also shut down, police announced at around 2:07 PM on Twitter.
Media reports and witness accounts, which have not yet been confirmed by police, say that the attacks took place in front of a synagogue in the city and that there had also been a blast in a Jewish cemetery.
The attacks on Wednesday coincided with the religious holiday of Yom Kippur, observed by Jews worldwide.
Eyewitnesses on the scene reported seeing a man in a combat suit with an automatic weapon, German daily Süddeutsche Zeitung (SZ) reports.
Pictures and videos shared by bystanders on Twitter show alleged perpetrators of the shooting.
Two photos show a man wearing an army suit and helmet and carrying what appears to be an assault rifle approaching in the immediate vicinity of a kebab shop, while video in an apparent separate location shows a man, dressed similarly, stepping out of a vehicle and shooting several rounds out of a weapon not visible in the video.
A bystander told German tabloid Bild that “a man with army uniforms and a rifle” came into the doner kebab shop he was in and “threw something that looked like a grenade.”
“The thing bounced at the door frame, then he shot into the glass,” he said, adding that he had “locked himself in the bathroom” before hearing another bang and the arrival of police.
The federal ministry of the interior said the motive behind the shooting was unclear, and that an investigation had been opened by the attorney general, according to SZ.