At least two killed in synagogue shooting in Germany
Several shots were fired and the suspected assailants then fled in a car, police said in a tweet. They urged residents to stay in their homes or indoors.
The central train station has also been closed while the area is under lockdown, rail company Deutsche Bahn said.
A short time after the incident, police reported that one person had been arrested. They gave no information on that person. Pictures from the scene showed a body lying in the street behind a police cordon.
Police didn't give any further information, but said officers were out in force in the city hunting down the suspects.
They gave no details about the target of the attack and there were varying reports.
The Bild and Mitteldeutsche Zeitung newspapers reported that the shooting took place near a synagogue in the Paulus district.
Jews around the world were marking Yom Kippur, one of the holiest days in the Jewish calendar, on Wednesday.
According to Bild, a hand grenade was also flung into a Jewish cemetery.
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An eyewitness, Konrad Roesler, told news channel NTV he was in a Turkish restaurant about 600 metres (yards) away from the synagogue when "a man wearing a helmet and military uniform" flung a hand grenade at the store.
"The grenade hit the door and exploded," he said.
"(The attacker) shot at least once in the shop, the man behind me must be dead. I hid in the toilet and locked the door."
Speaking to NTV, a police spokesman said the motive of the suspect or suspects was not clear.
"We don't have any indication about the motive of this act."
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