The Monday shootings in Vienna join a litany of terror attacks suffered by the Austrian capital in past decades.
Resulting in at least 15 people injured, with seven in serious condition and causing the police department and Austrian military to launch a massive operation, the attack was described by Austrian authorities as a terror act.
Commenting on the incident, Chancellor Sebastian Kurz named it a "hideous terrorist attack" and vowed to take "decisive action".
Here is what is known about terror attacks in the Austrian capital over past decades.
1975 OPEC Siege
During the 21 December 1975 semi-annual meeting of OPEC leaders in Vienna, six militants took over 60 hostages, killed an Austrian policeman along with an Iraqi OPEC security officer and a Libyan economist, and wounded several other people.
Led by Carlos the Jackal, the group behind the attack named itself the "Arm of the Arab Revolution".
In following years, members of the Carlos group revealed that the siege was commanded by Wadie Haddad, a founder of the Popular Front for the Liberation of Palestine, claiming that the idea was suggested and funded by "an Arab president".
Carlos the Jackal was captured in Khartoum, Sudan, and is serving a life sentence for at least 16 other murders.
1981 Synagogue Attack
The Vienna synagogue, near which the 2020 attack took place, was targeted by terrorists in 1981, as two Palestinian gunmen with a machine gun and grenades killed two people and wounded thirty attending a Bar mitzvah service.
The attackers were identified as Marwan Hasan, 25, from Jordan, and Hesham Mohammed Rajeh, 21, born in Iraq. Both were convicted of murder and attempted murder.
1985 Rome and Vienna airport attacks
In 1985, both Rome and Vienna suffered airport attacks by seven Arab terrorists on 27 December. During the attacks assault rifles and hand grenades were used.
The attack claimed nineteen civilian lives and injuring hundreds of others before the four terrorists were killed by El Al security personnel as local police capturing the other three.
2009 Temple Attack
On 24 May 2009, the Guru Ravidass Gurdwara temple in Vienna saw an attack carried out by six men carrying knives and guns. At least 15 people were injured, while two people, identified as visiting Dera Sach Khand head Niranjan Dass, 68, and another leader, Rama Nand, 57, suffered multiple gunshots and died in hospital.
Among the injured were the four attackers, who were eventually subdued by other worshipers in the temple.
The attack sparked riots in northern India.