austria terror
© AP Photo/Matthias SchraderA military police officer guard at the crime scene near a synagogue in Vienna, Austria, Wednesday, Nov. 4, 2020. Several shots were fired shortly after 8 p.m. local time on Monday, Nov. 2, in a lively street in the city center of Vienna.
Slovakian intelligence told their Austrian counterparts in July that the gunman who killed four people in a terror attack in Vienna this week had tried to buy ammunition there and mistakes were apparently made in dealing with that information, Austrian authorities have conceded.

The suspect, identified as 20-year-old Kujtim Fejzulai, had a previous conviction for trying to join the so-called Islamic State group in Syria and had been given early release in December.

In addition to killing two men and two women, he wounded more than 20 people in a nine-minute attack before being killed by police on Monday night. Bars and cafes were crowded with people enjoying warm weather and a last evening out before a new coronavirus lockdown.

The attacker was armed with an automatic rifle, a handgun and a machete, and wore a fake explosives vest.

austria terror
© Matthias Schrader/APBullet holes at the scene
A full assessment of copious video evidence has confirmed he was a lone assailant, interior minister Karl Nehammer said.

Austrian officials say Fejzulai, a dual citizen of Austria and North Macedonia, fooled the justice system's de-radicalisation programme after his release, and Mr Nehammer said on Wednesday that other things appeared to have gone wrong.

Slovak intelligence informed Austria that Fejzulai was trying to buy ammunition, and "something apparently went wrong with the communication in the next steps", Mr Nehammer said, adding that he would propose that an independent panel to be set up to examine "where things happened that shouldn't have happened".

In neighbouring Slovakia, police said they received information during the summer about "suspected persons from Austria" trying to buy ammunition.

"They failed to make the purchase," they said. "We immediately sent the information to our Austrian colleagues."

Austrian public security director Franz Ruf said his intelligence officials received the information and asked questions of their Slovak counterparts, but it is unclear "whether the process went optimally".

Fourteen people associated with the attacker were detained on Tuesday for questioning. Mr Nehammer said their ages range from 18 to 28 and all have immigrant roots. Some do not have Austrian citizenship.

Police in the Swiss city of Winterthur said on Tuesday that two men had been arrested there. Swiss news outlet St Galler Tagblatt reported that justice minister Karin Keller-Sutter described them as "colleagues" of the attacker.

Mr Ruf said Austrian authorities are in close contact with their Swiss counterparts.

The assailant attended school in Vienna for years and until recently lived with his parents in the city, Mr Ruf said.

In August 2018, Fejzulai tried to travel to Afghanistan to attempt to join IS, but was turned back because he had no visa.

In September of the same year, he travelled to Turkey to try to join the extremist group, but was detained and held for months by Turkey before being returned to Austria in January 2019, when he was arrested at the airport.