Austrian police made 30 arrests in more than 60 raids on Monday as part of an anti-terrorism operation, but there was no link to a deadly attack in Vienna a week ago in which a convicted jihadist killed four people, prosecutors said.
Austria has formally remanded in custody 10 suspects in connection with the attack by a 20-year-old gunman who had previously been convicted of trying to join Islamic State in Syria. Police shot him dead minutes after he opened fire on bars and bystanders in central Vienna.
Monday's raids on apartments, houses, businesses and association premises in four Austrian provinces targeted people suspected of belonging to or supporting the Palestinian Islamist movement Hamas and the Muslim Brotherhood, the prosecutors' office in the southern city of Graz said.
"The suspicion is of belonging to a terrorist organisation, financing terrorism, association against the state, criminal organisation and money laundering," it said in a statement, adding that the investigation had begun more than a year ago.
Hamas, which won the last Palestinian parliamentary election in 2006, was founded as the Palestinian branch of the Muslim Brotherhood.
Hamas is designated a terrorist organization by the United States and European Union. The Muslim Brotherhood is not on the bloc's terrorism blacklist but prosecutors said they were investigating links between the two organisations.
Monday's raids were carried out in four of Austria's nine provinces: Styria, of which Graz is the capital, Carinthia, Vienna and Lower Austria.
Prosecutors are investigating more than 70 people on suspicion of of belonging to and supporting Hamas and the Muslim Brotherhood, the prosecutors' office said.