Two people were arrested near Vienna on Tuesday, according to the APA news agency, as police hunted accomplices of a gunman or gunmen who killed four people in what the government called an Islamist terrorist attack in the Austrian capital.
In an early morning televised news conference, Interior Minister Karl Nehammer repeated calls for the public to stay off the streets.
APA quoted police as saying two arrests had been made in the nearby town of St Poelten. The Kurier news site reported that heavily armed police had searched two properties.