It is not yet known how many British nationals are among those caught up in the aftermath of a huge blast in the Lebanese capital, Beirut, the Foreign Office has confirmed.
Prime Minister Boris Johnson said the Government is “ready to provide support in any way we can”, while the Foreign Office said it is “monitoring the situation closely”.
The Queen sent a message to the President of the Republic of Lebanon to say she and the Duke of Edinburgh were “deeply saddened” by the news.
Schools Minister Nick Gibb said that all embassy staff based in Beirut are accounted for, but that some have suffered “non-life-threatening injuries”.
The blast, which happened on Tuesday, killed at least 100 people and injured more than 4,000 others. More than 100 people are believed to be missing.
Assistant director for crisis management at Red Cross Lebanon Rodney Eid said he expects the death toll to rise.
Lebanon President Michel Aoun said the blast was caused by 2,750 tonnes of ammonium nitrate being stored unsafely in a warehouse.
In a tweet on Tuesday evening, Mr Johnson said: “The pictures and videos from Beirut tonight are shocking. All of my thoughts and prayers are with those caught up in this terrible incident.
“The UK is ready to provide support in any way we can, including to those British nationals affected.”
Foreign Secretary Dominic Raab said the UK stands in solidarity with Lebanon.
“My thoughts and prayers are with those affected by the devastating explosion in Beirut today.
“The UK stands in solidarity with the people of Lebanon and is ready to offer help and support, including to those British nationals impacted,” he said.
The Queen’s message to Mr Aoun said: “Prince Philip and I were deeply saddened by news of the explosion at the Port in Beirut yesterday.
“Our thoughts and prayers are with the families and friends of those who have been injured or lost their lives, and all those whose homes and livelihoods have been affected.”
Labour leader Sir Keir Starmer said: “The images of explosions in Beirut are deeply worrying. Our thoughts are with those affected, the emergency services and the people of Lebanon.”
A spokesman for the Foreign Office said: “All embassy staff are accounted for. A small number have sustained non-life-threatening injuries and, where necessary, are receiving medical attention.
“It is a fast-moving situation and we are monitoring the situation closely. We stand ready to offer consular support to British nationals affected.
“People should check FCO travel advice, which is updated regularly and includes contact details for those requiring consular assistance.”
Tory Defence Select Committee chairman Tobias Ellwood said the Government should offer the services of the UK’s hospital ship, RFA Argus, to Lebanon.
In a tweet, he said: “With Beirut hospitals overwhelmed (injured being treated in car parks) this asset should be part of our support offered to Lebanon.”
Abbas Ibrahim, chief of Lebanese General Security, said the blast might have been caused by highly explosive material that was confiscated from a ship some time ago and stored at the port.
But US President Donald Trump said US military generals had told him they “seem to feel” the explosion was the result of a “terrible attack” most likely caused by a bomb.
“It would seem like it based on the explosion,” Mr Trump told reporters in Washington.
Mr Gibb said the US President was “premature to speculate”.
“The Lebanese government have announced that they are conducting an inquiry and we are ready to help support the Lebanese government with any technical support that they need, but this is a tragedy and the Lebanese authorities are, of course, investigating the cause of that tragedy and I think before we have the results of that inquiry, I think it is premature to speculate,” he told Sky News.”
Mr Gibb went on: “We are, as a Government, working urgently this morning on what support we can offer to the Lebanese government, whether that is technical support or financial support.”
He added that the Government “don’t know yet” how many British nationals are affected and that “the prime minister of Lebanon has asked for assistance”.
Former Middle East minister Alistair Burt said he expects the tragedy to lead to “some degree of political shake-up” in Lebanon.
“Whether or not something like this does bring the political processes in Lebanon together to appreciate they can’t go on as they are, that will be another thing, but at the moment I think we should focus on the disaster consequences, be as supportive as possible in relation to that,” he told BBC Radio 4’s Today programme.
“But I would imagine it will require some degree of political shake-up as well.”