Emergency services were called in to the US embassy in Cyprus on Monday after a suspect package was received, in the latest security alert to hit a US mission abroad, police said.
"An envelope of unknown content was taken by the fire service and sent to the state lab and the health services for testing," a police spokesman told AFP.
The official said the US embassy in Nicosia alerted the fire brigade who then also called in the police as a matter of security protocol.
Cyprus fire brigade spokeswoman Lisa Kemidji told AFP that two fire vehicles were dispatched to the scene and that officers wore chemical suits as a "precaution".
She would not speculate on what might be in the suspect item.
"We don't know what was in the package. It will be opened by health services officials," she said.
A US embassy source said that its services had not been disrupted by the scare.
There has been a spate of security alerts at US offices at home and overseas in recent weeks sparked by envelopes containing white powder.
More than 40 US governors' offices and 18 US embassies around the world have been affected.
Embassies have been on high alert for suspect mail ever since letters containing anthrax killed five people and spread panic in 2001.