The eight, including five Yemenis, two Syrians and prime defendant Anwar Bayan Sadiq al-Gaylani, an Iraqi, are in custody, charged with plotting to attack the British and Italian embassies and the French cultural centre.
Documents presented to the court on Monday alleged the group planned to target foreign banks, American fast food chains, Red Cross offices, DHL offices and western teachers, managers and doctors.
Prosecutor Said al-Aqil said the were to take place in Saudi Arabia, United Arab Emirates, Qatar, Kuwait, Bahrain and Yemen.
Most of the defendants have previously denied plotting such attacks.
The suspects, including two Yemeni brothers, were detained in a crackdown on terrorism during recent months.
The eight are among 13 suspected al-Qaida members detained in Yemen recently.
Five were released, including a Yemeni woman, for lack of evidence.
Police found hand grenades, military fatigue and documents showing sketches of sites to be attacked.
The trial was adjourned to May 16.