Terrorists opened fire in at least six locations in Vienna, Austria, on Monday evening, including outside a synagogue.

Police confirmed that several shots were fired, beginning at Seitenstettengasse, around 8:00 p.m. local time. It said there were several suspects armed with rifles at six different shooting locations.

The Interior Ministry initially confirmed that two people were killed, one of them a terrorist. At least 15 people were injured, seven of them seriously.

Vienna Mayor Michael Ludwig said later on Monday night that a woman wounded in the attack died of her injuries, bringing the civilian death toll to two.

Austrian Interior Minister Karl Nehammer said the terrorists who carried out the attack in Vienna are “heavily armed and dangerous” and that at least one of them is still on the loose.

He warned people to stay away from the center of the city, adding that border checks were being reinforced and that children would not be required to attend school on Tuesday.

“We have brought several special forces units together that are now searching for the presumed terrorists. I am therefore not limiting it to an area of Vienna because these are mobile perpetrators,” Nehammer told local media.

The head of the Jewish community in Austria, Oskar Deutsch, wrote on his Twitter account that the Jewish institutions in Vienna would be closed on Tuesday following the attack.

"All Jewish schools, synagogues and Jewish community institutions, as well as kosher restaurants and supermarkets in Vienna will be closed as a precautionary measure," Deutsch wrote, adding that it is not yet clear if the attack was anti-Semitic.

Earlier, it was reported that bystanders fled the scene after multiple shots were fired outside the Seitenstettengasse Temple, the main synagogue in Vienna. According to unconfirmed initial reports from Vienna, the attack targeted the synagogue, which was empty. Security at the synagogue fired back and the shooter continued to attack people eating outdoors in a restaurant.

There were reportedly two shooters, one of whom escaped. The second shooter was killed, with unconfirmed reports that he detonated a suicide belt.

Police are at the scene and are conducting a large operation to capture the surviving shooter.

According to one report, up to ten terrorists took part in the attack.

Austrian Chancellor Sebastian Kurz condemned the shootings as a “repulsive terror attack”, adding that the army would protect sites in the capital so the police could focus on anti-terror operations.

“We are currently experiencing difficult hours in our republic. I would like to thank all the emergency forces who are risking their lives for our safety, especially today. Our police will take decisive action against the perpetrators of this repulsive terrorist attack,” Kurz wrote on Twitter.

Channel 12 News' Elad Simchayoff tweeted following the shooting: "I've heard reports from individuals with knowledge of the shooting in Vienna that the Great Synagogue in the city along with the nearby Jewish restaurant were locked [at the time of the shooting]. The synagogue is thoroughly secured. It appears - and this is the assumption at the moment- that the incident may have been a criminal attack, and synagogue security may have intervened. As previously stated, the investigation is ongoing and the attacker seems to have escaped."

The Jewish community has instructed its members not to leave their homes while the remaining shooter is still on the loose.

Alon Ben David of Channel 13 News reported that the assessment in Israel at the moment is that the attack in Vienna was not aimed at Jews.

Police have asked the public not to share videos from the scene on social media so as not to endanger officers or civilians while the operation remains ongoing.

The Seitenstettengasse Temple was was the target of two attacks by Palestinian Arab terrorists in 1979 and 1981, the latter of which killed two people.