Its a 110% american operation.Few days after O'ma said he will send more drone to attack Waziristan, in answer to the fact that he was asked not to defy Pakistan air space any more.
A group of more or less 12-20 american trained army went in and targeted the P3 C Orion for the soul purpose of rendering Pakistan helpless against future drone attacks.
and their second main target was the chinese diplomats that were at the base at the time.Coz, US always wanted ruin China and Iran's relationship with pakistan.