Iran's 86-year-old Supreme Leader Ayatollah Ali Khamenei cuts an increasingly lonely figure, Reuters reported.

Khamenei has seen his main military and security advisers killed by Israeli air strikes, leaving major holes in his inner circle and raising the risk of strategic errors, according to five people familiar with his decision-making process.

One of those sources, who regularly attends meetings with Khamenei, described the risk of miscalculation to Iran on issues of defence and internal stability as "extremely dangerous".

Several senior military commanders have been killed since Friday including Khamenei's main advisers from the Revolutionary Guards, Iran's elite military force: the Guards' overall commander Hossein Salami, its aerospace chief Amir Ali Hajizadeh who headed Iran's ballistic missile program and spymaster Mohammad Kazemi, according to Reuters.