Austrian police stepped up security in Vienna and other cities on Saturday after receiving a warning of possible attacks during the holiday season.
Reports say a “friendly” intelligence service sent a warning to many European capitals saying a shooting or bomb attack could take place in crowded areas between Christmas and New Year.
They say the warning included “several names of potential attackers” but investigations have so far led to no concrete results.
In response to the alert, police have increased security at public events and roads, while asking Austrians for their understanding for more controls.
The warning comes after gunmen and suicide bombers killed 130 people in a series of coordinated attacks in Paris last month.