General Qassem Soleimani, head of Tehran's elite Quds Force who spearheaded military operations in the Middle East, was targeted in a drone strike at Baghdad's international airport today.

The US Defence Department insisted Gen Soleimani was targeted because he was ‘actively developing plans to attack American diplomats and service members’ in the region.

The attack sparked a furious response from Iran’s supreme leader Ayatollah Ali Khamenei who today warned ‘severe revenge awaits the criminals’ behind the strike.

Sign up to our daily newsletter The i newsletter cut through the noise Sign up Thanks for signing up! Sorry, there seem to be some issues. Please try again later. Submitting...

General Qassem Soleimani, commander of Iran's Quds Force, attends an annual rally commemorating the anniversary of the 1979 Islamic revolution, in Tehran, Iran. The U.S. airstrike that killed a prominent Iranian general in Baghdad raises tensions even higher between Tehran and Washington after months of trading attacks and threats across the wider Middle East. (AP Photo/Ebrahim Noroozi, File)

British foreign secretary Dominic Raab has since pleaded for calm and urged ‘all parties to de-escalate’.

‘Further conflict is in none of our interests,’ he said in a statement.

But a former British Army officer from Cowplain, who was a leading figure in the UK’s military during the last Iraq war, has warned the crisis was reaching boiling point.

Lieutenant Colonel Chris Parker backed US president Donald Trump’s attack but warned the American government’s move to pull its citizens out of Iraq was a worrying sign of things to come.

This photo released by the Iraqi Prime Minister Press Office shows a burning vehicle at the Baghdad International Airport following an airstrike, in Baghdad, Iraq, early Friday, Jan. 3, 2020. The Pentagon said Thursday that the U.S. military has killed Gen. Qassem Soleimani, the head of Iran's elite Quds Force, at the direction of President Donald Trump. (Iraqi Prime Minister Press Office via AP)

Speaking to The News, he said: ‘There is concern now. I have a lot of friends in Baghdad. There is talk of people moving.

‘US citizens are being told to get out of Iraq. That’s not something done lightly. It’s likely been made because there is something big coming in the winds and it is going to hurt.’

Hundreds of soldiers from 1st Battalion, Princess of Wales’s Royal Regiment, which recruits from Portsmouth, are stationed in Cyprus to act as Britain’s regional standby unit in the Middle East.

Lt Col Chris Parker pictured in Iraq.

Lt Col Parker, who is chairman of the Princess of Wales’s Royal Regiment Association, thought it would be unlikely the soldiers would be sent into direct conflict.

However, he said the infantry regiment could potentially be used to help evacuate British citizens if the crisis escalated further, adding the drama in Iraq was ‘frighteningly similar’ to training scenarios used to prepare Britain’s military.

‘The battalion is well trained and very experienced and a lot of senior commanders have served in operations in the Middle East,’ he said.

‘If the battalion is called to do anything I can’t imagine there will be any risk of them being deployed on mass to the Middle East.

Police officers outside the Iranian Embassy in Knightsbridge, London, after the US killed General Qassem Soleimani in a drone strike at Baghdad's international airport. Photo: Aaron Chown/PA Wire

‘That’s not to say they won’t be called to protect or extract British citizens. That’s happened before in Lebanon.’

But Labour leadership hopeful Clive Lewis, who served as a Territorial Army officer and completed a tour of duty in Afghanistan, warned the ‘violent escalation in an already volatile region is a mistake’ should not be ‘compounded’ by UK support.

‘I call on the PM to condemn this cowboy action & turn immediately to our international institutions to try & de-escalate any war with Iran,’ the former shadow defence secretary tweeted. ‘The UK must now lead in being a broker for peace.’

Prime minister Boris Johnson, who has been celebrating New Year on the private Caribbean island of Mustique, is yet to comment.

Tensions have been simmering between the US, the UK and Iran since May after the Royal Navy seized an Iranian-flagged ship near Gibraltar.

In retaliation, Iran captured the British-flagged vessel the Stena Impero.

Hundreds of Royal Navy sailors – including scores from Portsmouth – are currently based in the Gulf and have been called upon to protect shipping in the Strait of Hormuz from Iranian gunships.

The MoD said about 400 British troops are deployed in Iraq across three main bases – Camp Taji near Baghdad, Union III in Baghdad, and Erbil in Iraqi Kurdistan.

There are also about 500 personnel at RAF Akrotiri in Cyprus where fast jets and reconnaissance planes fly out over Iraq and Syria, the department added.