The Chinese postal service has offered to help investigate the source of mysterious packages of seeds that have been appearing in people's postboxes in the United States.
Residents across the US have reported receiving unsolicited packages from China, often marked as containing toys or jewellery.
The types of seeds have yet to be identified and agriculture officials have warned residents not to plant them in case they prove to be harmful or invasive species.
On Tuesday, Chinese foreign ministry spokesman Wang Wenbin told a regular press briefing: "China Post has asked the United States Postal Service to return this faked mail to China so China can investigate."
Wang said information labels on the packages appeared to be forged, according to checks by China's postal service, adding that there were errors in the information attached to the packages.