Downing Street has confirmed the Prime Minister is being updated on the situation in Afghanistan and will conduct a security meeting later today. The worrying development comes as the US Pentagon confirmed there had been at least two deadly blasts near the refugee evacuation airport in Kabul.

       Pentagon spokesman John Kirby confirmed one explosion took place near the Abbey Gate of Hamid Karzai International Airport.

       A number of US and Afghan civilians are understood to have been killed.

       Mr Kirby also said at least one other explosion was reported near the nearby Baron Hotel in the capital.

       He tweeted: "We can confirm that the explosion at the Abbey Gate was the result of a complex attack that resulted in a number of US & civilian casualties.

       "We can also confirm at least one other explosion at or near the Baron Hotel, a short distance from Abbey Gate. We will continue to update."

       A Taliban official said at least 13 people had been killed, including children, and many Taliban guards were wounded.

       A British defence source told Sky News it is “highly likely” that an Islamic State group in Afghanistan, known as Isis-K, is responsible for the attack.

       Armed Forces minister James Heappey had earlier warned there was "very credible reporting" of an "imminent" and "severe" terror threat.

       On Wednesday night, the Foreign Office urged UK nationals near Kabul airport to leave and head for safety due to an "ongoing and high threat of terrorist attack".

       Following the attack, the Ministry of Defence has said it is "working urgently" to establish what happened in Kabul and "its impact on the ongoing evacuation effort".

       A statement added: "Our primary concern remains the safety of our personnel, British citizens and the citizens of Afghanistan."

       Conservative MP Tom Tugendhat, who served in Afghanistan, said the attack in Kabul showed "the horror of Taliban rule".

       The chairman of the Commons Foreign Affairs Select Committee tweeted: "The attack on innocent people at Kabul airport simply trying to escape the horror of Taliban rule shows exactly who the group has brought with them.

       "The pattern is well established - from Nigeria and Mali to Syria and Iraq, whenever Islamist extremists take power, terror follows."

       Labour leader Sir Keir Starmer tweeted: “Devastating reports from Kabul. Our thoughts are with all those killed and wounded, serving personnel supporting the evacuations and all those desperately trying to leave.

       “The bravery of the troops at the airport will always outweigh the cowardice of those who wish to harm us.”

       Some 1,988 people have been evacuated from Kabul in the past 24 hours, Mr Heappey said.

       The UK has now rescued more than 12,000 Afghans since the Taliban took over control.

       This is a developing news story, more to follow.