The leader of the Democrats in the US Senate has called for a "full investigation" after the White House confirmed that a journalist was included in a group chat in which US Defence Secretary Pete Hegseth and other top officials discussed upcoming strikes against Yemen's Houthi group.
US President Donald Trump announced strikes on 15 March, but in a shocking security breach, The Atlantic magazine's editor-in-chief Jeffrey Goldberg wrote that he had hours of advance notice via the group chat on Signal.
The US airstrikes killed 53 people and wounded 98 others, according to the health officials in Yemen.
"The message thread that was reported appears to be authentic, and we are reviewing how an inadvertent number was added to the chain," National Security Council spokesman Brian Hughes said.
Mr Goldberg did not provide details of the plan, but wrote that Mr Hegseth sent information on the strikes, including on "targets, weapons the US would be deploying, and attack sequencing," to the group chat.
"According to the lengthy Hegseth text, the first detonations in Yemen would be felt two hours hence, at 1.45pm eastern time," Mr Goldberg wrote - a timeline that was borne out on the ground in Yemen.
Mr Goldberg said he was added to the group chat two days earlier, and received messages from other top government officials designating representatives who would work on the issue.
On 14 March, a person identified as Vice President JD Vance expressed doubts about carrying out the strikes, saying he hated "bailing Europe out again," as countries there were more affected by Houthi attacks on shipping than the United States.
Group chat contributors identified as National Security Adviser Mike Waltz and Mr Hegseth both sent messages arguing only the US had the capability to carry out the mission, with the latter official noting that he shared Mr Vance's "loathing of European free loading".
And a person identified as "S M" - possibly Trump adviser Stephen Miller - argued that "if the US successfully restores freedom of navigation at great cost there needs to be some further economic gain extracted in return".
Officials 'committed a crime'
The security breach provoked outrage among Democratic politicians, including Senate minority leader Chuck Schumer who slammed the inadvertent sharing of the Pentagon war plan.
"This is one of the most stunning breaches of military intelligence I have read about in a very, very long time," Mr Schumer said.
"This debacle requires a full investigation into how this happened."
Mr Trump has claimed he knew nothing about the security breach.
"I don't know anything about it," Mr Trump told reporters when questioned on the incident earlier today. "You're telling me about it for the first time."
In a statement issued this evening, the White House said that Mr Trump still backs his national security team despite the blunder.
"President Trump continues to have the utmost confidence in his national security team, including National Security Adviser Mike Waltz," spokeswoman Karoline Leavitt said in a statement.
The Houthis, who have controlled much of Yemen for more than a decade, are part of the "axis of resistance" of pro-Iran groups staunchly opposed to Israel and the United States.
They have launched scores of drone and missiles attacks at ships passing Yemen in the Red Sea and Gulf of Aden during the Gaza war, in solidarity with the Palestinians.
The Houthis' campaign crippled the vital route, which normally carries about 12% of world shipping traffic, forcing many companies into a costly detour around the tip of southern Africa.
The US began targeting the Houthis in response under the previous administration of former president Joe Biden and has launched repeated rounds of strikes on Houthi targets, some with British support.
Mr Trump has vowed to "use overwhelming lethal force until we have achieved our objective," citing the Houthis' threats against Red Sea shipping, and US strikes have continued over the past ten days.
