Suspicious envelopes containing a white powder and notes were sent to the US, Spanish and Swedish embassies in Tel Aviv on Tuesday, police said, adding that there were no reports of anyone hurt.

“The embassy received a letter with white powder today,” Swedish foreign ministry spokesperson Camilla Åkesson-Lindblom told The Local in Stockholm.

“The embassy is temporarily closed and all non-essential staff have been sent home.”

Åkesson-Lindblom had no comment regarding possible threats against the Swedish mission in Israel. Nor could she say how long the embassy would remain closed.

Israeli police spokesman Micky Rosenfeld said police were investigating the incident, and checking to see what the powder was. However, he said none of the embassy people appeared to have been harmed.

“Three separate envelopes were sent to three different embassies — the American, Spanish and Swedish — and in each they were opened by embassy staff who found a suspicious powder” he said.

Rosenfeld provided no details on the content of the notes or who might be behind the incident.

“A suspicious envelope was found and our security is working with the local police to sort it out,” US embassy spokesman Kurt Hoyer told AFP, without providing further details.

Letters containing a white powder have been considered a potential deadly threat since five people were killed in the United States when anthrax spores were mailed to some news media offices and US senators in the weeks following the September 11, 2001 attacks.

The FBI closed its investigation following the 2008 suicide of the main suspect, a researcher at the US Army Medical Research Institute of Infectious Diseases.

Hoaxes, that became known as “white powder events,” became frequent following the anthrax attacks.