Horror mass shooting Vienna

Vienna Police urged everyone to stay away from the city centre after confirming there were "several injured persons" due to the shooting.

“We are on site with all available forces. Please avoid all public squares in the city,” police said.

In its most recent update, police confirmed "several perpetrators" with rifles were behind the attack, there were a total of six crime scenes and one attacker had been shot dead by anti-terror officers. Another attacker is believed to still be "on the run".

Police also confirmed there was at least one fatality and several people were seriously injured, including a police officer.

The situation is still unfolding with police asking everyone in the city to keep their doors locked.

Local media is reporting there could be more casualties from the horrific attack, with up to seven feared dead.

In one video seen by news.com.au, a man dressed in white and armed with an assault rifle can be seen approaching a man, dressed in black, stuck on the street.

Despite the man dressed in black attempting to shield his body in a window alcove, the armed man shoots him and runs off.

The shooter returns to the street a short time later and sees the man in black on the ground and fires another shot at him.

A number of police officers are then seen on CCTV approaching the man in black and rendering first aid.

Austria has officially called the incident a terror attack.

Chancellor Sebastian Kurz said in a tweet that police were taking "decisive action against the perpetrators of this hideous terrorist attack".

"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," Mr Kurz said, in the translated tweet.

Mr Kurz said the military was protecting property across the city to allow police to "concentrate fully on the fight against terrorism".

Interior Minister Karl Nehammer also labelled the incident a terror attack.

“At the moment I can confirm we believe this is an apparent terror attack,” he told Austrian broadcaster ORF.

“We believe there are several perpetrators. Unfortunately there are also several injured, probably also dead.”

The first shots were fired just before 8pm local time with the police operation stretching more than three hours.

Gunshots were reported near Schwedenplatz, one of the main squares in the Austrian capital.

Local media is reporting explosives were involved in the attack.

Dozens of police were filmed running through the city in an attempt to find more active shooters with heavy gunfire heard.

In one video, police in protective gear can be seen rushing through local restaurants, as diners lie flat on the ground, in search of any potential shooters.

Video footage taken by a Vienna local showed a pool of blood outside a cafe in the city's main Jewish centre.

Everyone has been ordered to stay inside, especially around the city's Jewish community after it was reported a synagogue, multiple restaurants and a Jewish community centre were targeted.

A man dressed in white, holding an assault rifle, was also filmed firing his gun towards someone.

Oskar Deutsch, the head of the Jewish community in Vienna, said the synagogue was closed when the shooting began but shots were fired "in the immediate vicinity" around it.

Ambulances are now on scene to help any victims of the shooting.

In recent years Austria has been spared the sort of large-scale attacks seen in Paris, Berlin and London.

In August, authorities arrested a 31-year-old Syrian refugees suspected of trying to attack a Jewish community leader in the country’s second city Graz. The leader was unhurt.

Tensions in Europe have been high recently after the beheading of French teacher Samuel Paty, who showed a caricature of Mohammed to his class.

Three people were also killed in Nice, in the south of France, last week in a terrorist attack outside the city's Notre Dame Basilica.

French President Emmanuel Macron tweeted his support for Austria and said his nation "shared the shock and grief of the Austrian people".

"It is a friendly country that is under attack. This is our Europe. Our enemies need to know who they are dealing with. We won't give in to anything," Mr Macron said in the translated tweet.