Austria closes mosque frequented by Vienna attacker

Austria has closed a mosque and an Islamic association frequented by a man who shot four people dead in a rampage through Vienna on Monday, integration minister Susanne Raab told a news conference on Friday.

She said the two sites had contributed to the attacker's radicalisation.

Interior Ministry officials said on Thursday said all 15 people arrested in connection with the deadly rampage in Vienna on Monday are part of the radical Islamist scene and just under half have criminal convictions, some for terrorism offences.

A 20-year-old native of the city, who had previously been jailed for trying to join Islamic State in Syria, was shot dead by police within nine minutes of opening fire on bystanders and bars on Monday.

"We are dealing with a violent perpetrator who was evidently intensely involved in the network of political Islam, of sympathisers, who took on their ideology," interior minister Karl Nehammer said.

The 15 are being held on suspicion of belonging to a terrorist organisation. Seven of them have criminal convictions, Of those, four are for terrorism-related offences, director general for public security Franz Ruf said.