Austrian prosecutors said on Sunday that another two suspects have been arrested for alleged involvement in the November 2 terrorist attack in Vienna, AFP reports.
The two men -- one of whom is a 26-year-old Austrian of Afghan origin -- were arrested on Friday, a spokeswoman for the prosecutors' office told the news agency. She declined to reveal the nationality of the other suspect.
The attack took place when an Islamic State (ISIS) supporter, who had been convicted and imprisoned for trying to join ISIS in Syria, went on a shooting rampage in central Vienna, killing four people, aged between 21 and 44.
The 20-year-old gunman, a dual Austrian-Macedonian national named Kujtim Fejzulai, was shot dead by police.
18 people have since been detained in Austria and Switzerland in connection with the attack and the government also ordered the closure of two mosques in Vienna frequented by the attacker.
Following the attack, it came to light that Austrian intelligence officials had been warned by their counterparts in neighboring Slovakia that Fejzulai had attempted to buy ammunition earlier this year.
It was also revealed that Fejzulai had been in contact with people who had been on the radar of the German intelligence agencies.
The security lapses resulted in the suspension of the head of anti-terror operations in Vienna.