BLASTS shook Baghdad when a projectile hit the Green Zone near the US embassy in the Iraqi capital last night.

More projectiles were fired at Balad Air Base north of Baghdad, which houses US forces. Reports suggest no one was hurt. 

Earlier in the day thousands of mourners marched in a funeral procession for Iran’s top general, chanting “death to America”.

Yesterday the Foreign Office strengthened travel warnings for Iran and Iraq, with British nationals in the region advised to “remain vigilant” after the US announced it was sending nearly 3000 extra troops to the Middle East.

Fears of an all-out war have been raised after Iran vowed harsh retaliation over the death of General Qasem Soleimani in a drone strike ordered by US President Donald Trump.

Yesterday the Foreign Office strengthened travel warnings for Iran and Iraq, with British nationals in the region advised to “remain vigilant” after the US announced it was sending nearly 3000 extra troops to the Middle East.

Despite the escalating tensions, Prime Minister Boris Johnson has yet to make any comment on the situation. A Downing Street spokeswoman yesterday said the Foreign Office was leading on the issue and she could not advise when Johnson might make a statement.

Labour MP Emily Thornberry described the Prime Minister's response as "pathetic".

He has been celebrating the New Year with partner Carrie Symonds on the private Caribbean island of Mustique and is expected to return to the UK early on Sunday.

READ MORE: PM and Carrie Symonds to spend New Year on Caribbean island of Mustique

Foreign Secretary Dominic Raab called for calm and urged all aggressors to de-escalate.

But Labour’s John McDonnell told a protest in Westminster yesterday that it was “not good enough” that the UK Government had not condemned Trump for authorising the killing.

The shadow chancellor promised to put pressure on Johnson concerning the attack, which he said will “set the Middle East and the globe alight yet again”.

He called for the UK Government to issue a “total and outright condemnation of this act of violence”.

He added: “We will not tolerate us being dragged yet again into this type of aggressive military action which puts us all at risk.”

Jeremy Corbyn has also written to the Prime Minister calling for an urgent meeting of the Privy Council, the group that advises monarchs.

The outgoing Labour leader said he wanted know if the “assassination” had heightened the terror risk to the UK and whether the Government had been informed of the decision to strike.

First Minister Nicola Sturgeon said: “This is an extremely worrying situation and we urge all parties to restrain from further violence and work to de-escalate tensions.

“Further conflict in the Middle East is in no-one’s interests.”

Trump claims he ordered the strike, which happened on Friday morning, to prevent a conflict.

READ MORE: Qasem Soleimani: Iran vows retaliation to US strike on top general

His administration says Soleimani was plotting a series of attacks that endangered American troops and officials – without providing evidence.

The UK Foreign Office warned that anyone in Iraq outside the Kurdistan Region should consider leaving by commercial means because the “uncertain” security situation “could deteriorate quickly”.

It also advised against all but essential travel to most of Iran – and against all travel to some areas including along the borders with Iraq and Afghanistan.

It states three days of mourning have been declared for Soleimani, with rallies and marches likely in cities across Iran, warning the “situation could become angry”.

British-Iranian dual nationals have been advised not to travel to Iran at all, with a risk they could be “arbitrarily detained or arrested”.

Three years ago, British-Iranian woman Nazanin Zaghari-Ratcliffe was imprisoned in the country on spying charges, which she denies, in a case which has sparked an outcry.

Alerts regarding other Middle East nations were also being increased, with calls for citizens to “remain vigilant” in nations including Afghanistan, Israel, Lebanon, Saudi Arabia and the United Arab Emirates.

Raab said the updated advice was issued due to “heightened tensions in the region” and would be kept under review. “The first job of any government is to keep British people safe,” he added.

The National: 'Death to America' has long been a favoured chant in Iran, but now it seems to be taking on a new dimension'Death to America' has long been a favoured chant in Iran, but now it seems to be taking on a new dimension

Soleimani masterminded Tehran’s regional security strategy, including the war against the Daesh terror group, and was blamed for attacks on US and allied troops.

Trump continued with his rhetoric despite widespread calls for calm, saying that Soleimani’s “reign of terror is over” and describing him as having a “sick passion” for killing.

A funeral procession for Soleimani and Abu Mahdi al-Muhandis – a senior Iraqi militia commander who was killed in the same strike – took place in Baghdad yesterday.

Mourners marched in the streets alongside militia vehicles in a solemn procession, many in tears, with chants of: “No, No, America,” and “Death to America, death to Israel”.

Hadi al-Amiri, who heads a large parliamentary bloc and is expected to replace al-Muhandis as deputy commander of the Popular Mobilisation Forces, an umbrella group of mostly Iran-backed militias, was among those paying their final respects.

Speaking beside al-Muhandis’s coffin, he warned: “Rest assured, the price of your pure blood will be the exit of US forces from Iraq forever.”

READ MORE: Qassem Soleimani: UK calls for calm after US strike on Iranian general

Iraq, which is closely allied with both Washington and Tehran, has called the air strike an attack on its national sovereignty.

Its parliament is to meet for an emergency session on Sunday, and the government has come under mounting pressure to expel the 5200 American troops based in the country, who are there to help prevent a resurgence of the Daesh group.

The US and France have also ordered all citizens to leave or avoid Iraq amid fears for their safety.

On Saturday, billboards appeared on major streets in Iran showing Soleimani and carrying the warning from Supreme Leader Ayatollah Ali Khamenei that “harsh revenge” awaits the US. Iranian President Hassan Rouhani, a relative moderate in the country’s political establishment, earlier visited Soleimani’s home in Tehran to express his condolences.

“The Americans did not realise what a great mistake they made,” Rouhani said. “They will see the effects of this criminal act, not only today but for years to come.”

There has been criticism of the US for not giving advanced notice of the attack to the UK, which has hundreds of troops deployed in Iraq.

Former foreign secretary Jeremy Hunt described an “incredibly dangerous game of chicken” between the US and Iran, which has simmered since Trump tore up a nuclear deal between the nations.

He said the tensions created a “very difficult situation” for the UK as an ally of the US, adding Britain “cannot afford to be neutral”.

But he added: “This is a very, very risky situation, and I think the job that we have to do as one of the US’s closest allies is to use our influence to argue for more consistent US policy.”