PARIS (AP) A French judicial official says that an anti-terrorism unit is investigating an unsigned letter received by Air China's Paris headquarters threatening reprisals if China does not free jailed Muslims.
A judicial official says the letter - written in English and unsigned - was received Friday, the opening day of the Olympic Games being hosted by China.
The official is not authorized to discuss investigations and customarily speaks to reporters on condition of anonymity.
The official said Tuesday the letter threatens reprisals if China does not free Muslim prisoners but does not provide further information on the letter or the threat.
A surge in violence in the mainly Muslim far western Xinjiang region coincides with the Olympics.