Austria has admitted “intolerable mistakes” in the handling of intelligence on the jihadist who killed four people in Vienna on Monday, saying it could have considered him a greater threat and monitored him more closely.

The head of the main domestic intelligence agency for the city of Vienna, the Vienna Provincial Office for the Protection of the Constitution and Counter-Terrorism (LVT), was stepping down temporarily while an investigation was carried out, Interior Minister Karl Nehammer told a news conference.