Austrian Chancellor Sebastian Kurz called on the European Union Tuesday (3 November) to do more to fight "political Islam", which he said represented a grave threat to European values.
"The EU must focus much more strongly on the problem of political Islam in the future," Kurz told the German daily Die Welt in an interview.
"I hope we will see an end to this misunderstood tolerance and that all countries in Europe will finally realise how dangerous the ideology of political Islam is for our freedom and the European way of life."
He was speaking a day after a known Islamic extremist went on a shooting rampage in Vienna, killing four people in Austria's first terrorist attack in decades.
Kurz said the EU "must, with utmost determination and unity, wage a war against Islamist terror, but particularly against its political base, that is to say political Islam."
The Austrian leader said he was in contact with French President Emmanuel Macron and "many other government leaders so that we can coordinate more closely within the EU."
Austria would put the issue on the agenda of upcoming EU summits, he added.
Islamic State -- which has claimed numerous attacks in Europe -- said Tuesday a "soldier of the caliphate" was responsible for the carnage, according to its propaganda agency.
Police shot the gunman dead on Monday and later swooped on 18 different addresses and made 14 arrests as they looked for possible accomplices and sought to determine if he had acted alone.
The police named the gunman as Kujtim Fejzulai, with North Macedonian and Austrian citizenship, described as a 20-year-old IS sympathiser who had spent time in prison.
After reviewing CCTV footage of the attack in an area teaming with bars and restaurants not far from the historic sights of central Vienna, Interior Minister Karl Nehammer said the video "does not at this time show any evidence of a second attacker".
Vienna police have asked people who filmed moment of the attack to share their recordings with the authorities to aid in tracking the gunman's route through the capital, rather than posting them to social media.
On Fejzulai's computer, investigators found incriminating evidence including a photograph recently posted on Facebook showing him carrying the automatic weapon and a machete used during the attack.
Police said he was also wearing a fake explosive belt.