Police officers are on duty on a street in Vienna, capital of Austria, Nov. 2, 2020. (Photo: Xinhua)

Austrian Interior Minister Karl Nehammer said Tuesday that there was so far no evidence of a second perpetrator involved in Monday evening's deadly terror attack in central Vienna.

Austrian police have collected some 20,000 videos. Experts are evaluating all of them, and over 50 percent have already been viewed, which did not at this time reveal any evidence of a second perpetrator, he told a press conference.

Since half of the videos have not been evaluated, Vienna is still placed under the highest security level, Nehammer said.

On Monday evening, at around 8:00 p.m. (1900 GMT), a terrorist attack took place in Vienna's inner city when an unknown number of gunmen opened fire on people enjoying a last-night out at Vienna's cafes and restaurants before the start of a coronavirus lockdown early Tuesday.

Four civilians were confirmed dead, and 22 others were injured in the attack, Nehammer said. A police officer who was seriously injured had received a successful operation and his condition is stable, he added.

Nehammer also said the 20-year-old perpetrator, identified by local media as Kujtim Fejzulai, was "quickly neutralized" and killed by police, which prevented worse things from happening.

Police have searched 18 locations in Vienna and Lower Austria, and 14 people have been arrested, he added.

National mourning

The Austrian government declared on Tuesday a three-day national mourning after the terror attack. Starting on Tuesday, flags have been lowered to half-mast on public buildings across the country, according to a government statement.

In addition, a "minute of silent remembrance" should be observed on Tuesday at 12 noon (1100 GMT). Schools should also observe a minute's silence at the beginning of lessons on Wednesday. A wreath-laying ceremony is planned in downtown Vienna.

"The Republic of Austria was, is and will always be a nation of diversity, dialogue and respect for one another, the more the events of November 2, 2020 have shaken and affected our country," said the government statement.

Also on Tuesday, the Chinese Embassy in Austria said that a Chinese Austrian was killed and a Chinese citizen injured in the terrorist attack.

The Chinese Austrian, owner of a restaurant in downtown Vienna, was badly injured in the attack and died on Tuesday morning, said the embassy. The wounded Chinese citizen, who works at the same restaurant, is in stable condition, it added.

Criminal contact record

At a press conference earlier on Tuesday, Nehammer said Fejzulai had a criminal record related to contact with the Islamic State (IS).

Fejzulai was sentenced to 22 months in prison on April 25, 2019, for attempting to travel to Syria to join IS and was released early on parole, local media reported.

Fejzulai was equipped with "a dummy explosive belt and an automatic long gun, a handgun, and a machete to carry out this hideous attack on innocent citizens," Nehammer said.

Austrian Chancellor Sebastian Kurz condemned the attack as a "hate attack". "Out of hatred for our core values. Out of hatred for our way of life. Out of hatred for our democracy, in which all people are equal in rights and dignity," he tweeted earlier on Tuesday.

"But we must always be aware that this is not a dispute between Christians and Muslims or between Austrians and migrants. This is a struggle between the many people who believe in peace and the few who want war," Kurz added.