Police in DC are investigating a "white substance" that was sent to former President Barack Obama's office space in the city.
The incident was reported around 12.30pm at 1250 24th St NW in DC, Fox 5 TV reported.
Fire and EMS Battalion Chief Edward Smith said the powder was delivered in a letter from Hong Kong and had no return address.
The substance is thought to be baby powder.
It is not clear if Obama was at the office at the time.
Obama has been leasing the space since he left the White House in January 2017, and uses it to conduct his business while in the capital. His home is located about a mile from his home in the nearby neighborhood Kalorama.
The building is owned and the headquarters for the non-profit World Wildlife Fund.
Police have said traffic in the surrounding area will be closed until everything is cleared up.
The incident comes just one day after a white substance was sent along with a threatening note to Donald Trump Jr's wife in New York.
Vanessa Trump was rushed to the hospital after she opened the letter and found the white powder.
The letter read: "You're an awful person and now you get what you deserve."
The substance turned out to be corn starch.
Both incidences have recalled the scary days after 9/11 when letters containing lethal anthrax spores were sent to the offices of several politicians and media outlets - resulting in five deaths.