Pakistan.
Lots of discussion here about the border dispute are debated on the shot down of Indian or Pakistan aircrafts and which kinds of fight jets are involved. Obviously, one MIG21 fight jet from the Indian Airforce was shot down yesterday by a Pakistan JF17 jet made in its plant using technologies of China. In fact, this jet has been developped by a joint project between Pakistan and China. No evidence for the involvement of F16 jets from the Pakisan AirForce has been presented so far. Also, a rumour was arround that a Su30 jet of Indian AirForce was down in the Indian side, what could be shot down (also by a Pakistan JF17 jet) or due to mechanic problems. This, however, needs further confirmed.
This event suggests that Pakistan AirForce has been skillfull and sucessful in using JF17 jets to combat with various jets from India including MIG21, SU30, and other types. It's amazed that the single engine light JF17 jets have shown such performance in the confrontation.