American businesses are being warned to protect themselves against Chinese hackers seeking revenge over the spy plane incident.
Cyber criminals claiming to be from China have already vandalised a few websites and US authorities warn things could get worse.
The hackers have left messages such as "For our pilot Wang" in support of the Chinese pilot who died in the collision with the US spy plane.
The FBI's cyber crime unit says Chinese hackers have publicly discussed increasing their activity from April 30 to May 7 - which coincides with two national holidays.
Website Attrition.org, which monitors cyber vandalism, says about 65 Chinese sites have already been targeted by American hackers who are leaving obscene and racist messages.
PA