At least two people were shot dead on a street in the German city of Halle on Wednesday, police said, with witnesses saying that a synagogue was among the gunmen's targets as Jews marked the holy day of Yom Kippur.
One suspect was captured but with a manhunt ongoing for other perpetrators, security has been tightened in synagogues in other eastern German cities while Halle itself was in lockdown.
"Early indications show that two people were killed in Halle. Several shots were fired," police said on Twitter, urging residents in the area to stay indoors.
Police said the "perpetrators fled in a car", adding later that one suspect had been caught.
Max Privorotzki, who heads the Jewish community in Halle, told Spiegel Online the perpetrators had apparently sought to enter a synagogue in the Paulus district but security measures in place helped to "withstand the attack".
He added that between 70 and 80 people were in the synagogue on a day when Jews around the world were marking one of the holiest days in the Jewish calendar.
Two people also suffered serious bullet wounds in the attack and were being operated on, a spokesman for the city's hospital said.
'Hid in the toilet'
Anti-terrorist prosecutors confirmed that they were taking over the probe given "the particular importance of the case" which he said involved "violent acts that affect the domestic security of the Federal Republic of Germany".
Bild daily reported that the shooting took place in front of the synagogue, and a hand grenade was also flung into a Jewish cemetery.
Witness Conrad Roessler 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" tossed a hand grenade.
"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."
Police would not confirm the details, saying only that there were also kebab restaurants and churches in the area where the shooting took place.