A man set himself on fire in front of the Israeli embassy on Sunday in Washington DC, US emergency services say.
The incident happened at about 13:00 local time (18:00 GMT) on Sunday.
Officers from the US Secret Service extinguished the flames before the man was taken to hospital with critical, life-threatening injuries, the city’s fire department reported.
A US Air Force spokeswoman was later quoted by US media as saying the man was an active-duty airman.
The Washington police department is now investigating alongside the Secret Service and other relevant authorities.
In a statement, police in the US capital said the incident happened at “the 3500 block of International Drive, NW, at approximately 1:00 pm”, and that officers were despatched to “assist the United States Secret Service after an individual set themselves on fire in front of an embassy in the block”.
The statement added that an “adult male” was then taken to hospital where he remained “in critical condition”.
A video has emerged on social media purportedly showing the man shouting “Free Palestine” as he burned, US media report.
A bomb disposal unit was sent to the site over concerns about a suspicious vehicle that could have been connected to the individual.
This was later declared safe after no hazardous materials were found.
No embassy staff members were injured in the incident, a spokeswoman for the embassy told the New York Times.
In a statement, the Israeli foreign ministry said the man was not known to embassy staff.
It is not the first time someone has self-immolated in front of an Israeli diplomatic mission in the US.
In December, a protester set himself on fire in front of the Israel consulate in the US state of Georgia.
Police said the demonstrator used petrol, and a Palestinian flag was found at the scene on that occasion.
By Agencies