Vienna - Austrian armed commandos arrested Friday a man suspected of planning a "terrorist" attack in Vienna, police said, with authorities deploying additional officers and warning the public to be vigilant."In recent days indications have grown of an actual suspect planning a supposed act of terror, and Vienna police... immediately began investigating and implemented security measures," spokesperson Irina Steier told AFP."The presence of uniformed and plainclothes police was increased and today at 18:00 (17:00 GMT) the suspect was arrested in Vienna near his address on the basis of an arrest warrant," Steier said.He gave no details of the suspect, except to confirm that it was a man and that investigations are continuing.The Kronenzeitung newspaper published online a document from the Interior Ministry saying that a group of "radical Islamists of Albanian origin" intended to launch an attack in Vienna.It said that according to information from a foreign intelligence agency and, independently from a foreign police force, the attack was to take place between January 15 and January 30.The document added that a German-speaking sympathiser of the Islamic State (ISIS) extremist group made explosives in Germany and that he intended to bring them to Vienna to carry out an attack.He was not immediately able to complete his travel plans, but the newspaper said that the suspect travelled from Germany to Austria on Friday."The man has been in custody... There are still lots of things to clear up," another police spokesperson, Thomas Keiblinger, told the Austria Press Agency, declining to comment further.Police also issued a public warning for people to be on the lookout at crowded public places and to inform police if they see any suspicious objects.Austria spared so far Austria has been spared in the string of attacks by Islamists suffered by other European countries but has increased security measures.In 2015 a record 90 000 people applied for asylum in Austria after hundreds of thousands of migrants transited the country bound for Germany and elsewhere.A Moroccan asylum-seeker was detained in Austria in December for allegedly planning an attack in Salzburg over the Christmas and New Year period, prosecutors said.The 25-year-old was arrested in a refugee centre in the small Alpine resort town of Fuschl, 20km east of Salzburg, close to the German border.Authorities had opened a probe in November after being tipped off about an "alleged terror attack in Salzburg around Christmas or New Year", it added.Police recovered more than €8 000 in cash and several electronic devices.Several of the attackers behind the November 2015 deadly attacks in Paris transited through Austria with false papers among the flow of migrants.In December 2015, an Algerian and a Pakistani were arrested in Salzburg and later extradited to France over their alleged intent to take part in those attacks, which left 130 people dead.And in September last year, Austrian police also detained two of their alleged accomplices, a Moroccan and an Algerian, in Salzburg. Their trial is set to begin on February 2.