Details are still very sketchy at this point. The Vienna police posted a message on Twitter about an hour ago (as I write this) saying shot had been fired in the city and people were injured:

Police are asking anyone with video of what happened not to post it online:

An Austrian news agency is reporting this as a possible terror attack and several news outlets are now reporting there may be two attackers, one of whom was killed:

According to the Austrian news agency APA, the Interior Ministry has spoken of a possible terror attack or shooting rampage. It said one attacker was dead and a police officer had been shot and seriously wounded, according to the agency. One suspected attacker has been arrested, the ministry was cited as saying.

Another aspect of this which may be leading authorities to suspect a terror attack is that the shooting apparently took place near a synagogue. However, the synagogue was closed so maybe it wasn’t the target:

The shooting reportedly took place on a street near a synagogue.

Jewish community leader Oskar Deutsch tweeted that it was unclear if the Vienna synagogue was targeted in the attack as it was closed at the time.

The Daily Mail is reporting that seven people have been killed in the attack:

At least seven people are thought to have been killed with several others injured in a suspected gun and suicide attack near a synagogue in Vienna.

A huge manhunt is underway for the gunman, according to local reports, with an accomplice thought to have ‘blown themselves up’ during the rampage.

Kronen Zeitung, Austria’s largest newspaper, is reporting the incident as a terror attack, with a police officer said to have been shot and left in a critical condition.

There are several videos circulating already. In this one a shooter comes out of some building and fires a few shots from a rifle.

There’s also this clip of what looks like the same person running down the street and firing a couple shots into the building. It looks to me like he’s passing the same red carpeted entrance seen above:

And in this clip you can see a shootout with two police officers, at least one of whom is hit. The reflection on the glass makes it hard to see but I think it’s the same shooter visible on the left of the frame:

Another video showing the shooter targeting a person in the street:

There are also a couple of videos where you can hear shots being fired but you can’t tell who is shooting:

A lot of blood in the street and people appear to be trying to help an injured person:

CNN is now reporting that there are multiple shooting locations and several suspects:

In a statement, police said there were several suspects “armed with rifles” and six different shooting locations. Multiple people have been injured in the city center.

“All possible forces” are responding to the incident, according to police, who are urging people to avoid the area and not to share photos or videos on social media.

From the NY Times:

At least 15 people were wounded in the attack, according to a spokesman for the local hospital association. It was unclear how serious the injuries were.

“At the moment we assume there are several perpetrators,” said Karl Nehammer, Austria’s interior minister. “Unfortunately there are also several injured, probably also dead.”

He called the episode a terrorist attack.

I’ll update this when more information is made available.

Update: The latest from Vienna police confirming some details about the attack.

Update: This is now being called a terror attack by Austria’s Chancellor so I’m talking the “possible” out of the headline. The top tweet reads: “We are currently going through difficult times in our republic. I would like to thank all the emergency services who risk their lives, especially today for our safety. Our police will take decisive action against the perpetrators of this hideous terrorist attack.”

The second tweet: “I am glad that our police officers have already been able to eliminate a perpetrator. We will never allow ourselves to be intimidated by terrorism and will fight these attacks resolutely by all means.”

Also, there’s a report that the shooter that was killed by police had an “explosive belt.”