The killing of top Iranian commander Qassem Soleimani by a US air raid has triggered a wave of emotions and garnered a united response of solidarity and retribution across the otherwise divided Iranian political spectrum, Eurasia Diary reports citing Aljazeera.

Soleimani, the head of Iran's elite Islamic Revolutionary Guard Corps' (IRGC) Quds Force and mastermind of its regional influence, was killed early on Friday near Baghdad's international airport in an air strike ordered by US President Donald Trump.

Iran's Supreme Leader Ayatollah Khamenei paid tribute to him as a "martyr" and promised to exact "harsh revenge".

He announced a three-day national mourning period in honour of Soleimani, who was widely believed to be the second most powerful figure in Iran.

Iranian President Hassan Rouhani echoed the threat of revenge and vowed that there will be consequences. Foreign Minister Javad Zarif condemned the killing as an "act of state terrorism" in a statement.

IRGC officials, clerics, ministers, members of parliament, and the business community reacted in unison and hailed the commander as a fallen hero.

Gatherings are being organised in Tehran and across the country after Friday prayers to commemorate Soleimani and denounce the US and Israel.

State broadcaster IRIB and radio channels were allotting almost their entire broadcast time to news of Soleimani's killing and programmes commemorating him. All television presenters wore black and a black stripe adorns the top corner of the screens.

All comedy films slated to be showed in cinemas were postponed and all music concerts were temporarily suspended.

A major passageway in Tehran, which has yet to be announced, will be named after Soleimani, officials said.