Hawzah News Agency - Ahmed al-Tayeb, the Grand Imam of Al-Azhar -- the highest seat of Sunni Muslim learning -- said in a statement that "killing one soul is as if killing all of humanity and the human right to life is one of the highest purposes in all laws."  

In Tunisia, the Ennahda movement, the largest parliamentary bloc, condemned the attack and called for "uniting international efforts to combat the scourge of terrorism, which does not exclude a country."

In a statement, the movement stressed that it "appreciates the positions of governments and officials and all voices stressing that these terrorist attacks are performed by extremist criminal groups that have nothing to do with Islam and Muslims."

Austria’s Interior Ministry announced that investigations revealed that the perpetrator of the attack was “a supporter of the terrorist organization ISIS” but no party has claimed responsibility.

Meanwhile, Iraqi Foreign Ministry spokesman Ahmed al-Sahaf said: "We offer our condolences to the government and people of Austria and we stress Iraq's position that rejects terrorism in all its forms and manifestations.”

Sudan said that "while offering sincere condolences and sympathy to the families of the victims, we express our full solidarity with the Austrian government and people.”

Lebanon’s Foreign Ministry condemned "all terrorist acts" and expressed "its sadness and pain for the deaths of innocent victims as a result of terrorist acts.”

Egypt’s Foreign Ministry also strongly condemned the terrorist attack and expressed its solidarity with the government and people of Austria.

Its statement stressed Egypt’s "categorical rejection of all forms of violence and extremism and its demand for the necessity of intensifying international efforts to confront terrorism."

Jordan’s Foreign Ministry meanwhile expressed its strong condemnation and denunciation of the terrorist crime and its solidarity with Austria in the face of blind violence and terrorism targeting the country's stability.

At least four people died and 17 others were wounded in the terrorist attack, authorities confirmed.

The wounded include a police officer, according to the Vienna Police Department.