Thousands of messages threatening retribution for the killing of Iran’s top intelligence commander have flooded social media in a “coordinated” propaganda campaign.

More than 21,000 Instagram posts used the hashtag #hardrevenge on Friday, along with almost 7,000 unique Twitter accounts, following the death of Qassim Soleimani, head of the elite Quds Force, by an American drone strike.

The accounts shared repetitive images of coffins draped in American flags, heroic depictions of Soleimani and photos of US military officials, such as Gen Mark Milley, chairman of the Joint Chiefs of Staff, with bullseye targets digitally imposed on their faces and the words “coming soon”. One widely-shared picture showed a beheaded Donald Trump.

According to Marc Owen Jones, a social media expert and professor of Middle Eastern studies, around 250 of the accounts were created after Soleimani was killed on Thursday, "a large proportion". The majority were created in recent months as tension escalated between Iran and the US, which Mr Jones described as "indicative of increased coordinated messaging campaigns".

Lee Foster, information operations analyst at cyber defence company FireEye, said that Iran had long been working on a disinformation army to rival Russia’s Internet Research Agency, as well as other tactics such as the creation of fake news outlets and "fabricated journalist personas".