Disgraced Pakistani nuclear scientist Dr Abdul Qadeer Khan has said Pakistan has the capability to shoot down unmanned surveillance drone aircrafts, adding that the country is facing internal threats rather than external.

He said they had built missiles in Kahuta some 15 years ago which have the capability to shoot down drone aircraft, reports The Nation."Pakistan''s defence looks very impenetrable externally, but it is internally vulnerable due to the internal situation of the country. We had planned that the nation would focus on progress, education and industrial advancement but rulers have plundered the public property for many years," Dr Khan was quoted, as saying.