The Queen’s Scottish residence is on lockdown this afternoon.
Emergency services have swooped on the Palace of Holyrood after a “suspicious letter” was sent.
It is reported the package that was delivered contained white powder along with a note.
A source told The Sun: “It was a letter that was sent and when opened a note and white powder was discovered.
“Due to the current alert it’s feared the white powder is some sort of harmful chemical.
“A full response has been initiated until it’s known exactly what the powder is.”
Ambulance and fire crews have been pictured at the popular tourist destination in the heart of the capital of Edinburgh.
A spokeswoman for Police Scotland said: “Police in Edinburgh were called to the Palace of Holyrood House around 12.05pm after reports were received that a suspicious letter had been delivered.
“Emergency services are in attendance and enquiries are ongoing.”