Which camera did you use for capturing the footages?
Do you have the folder structure intact? If not then copy the entire folder structure from the camera card & use media browser for importing the footages.
Also check if you have anything on the audio track when you create a new sequence from clip.
Check if your Premiere Pro version is upto date.
If you are using CS6 then try with CC.
Do you have audio when you play the clips in a media player like VLC?
Try the steps & let us know the results.
Thanks veyr much for your responses. I have spoken to online chat support and reso;ved the problem. I converted the files via adobe media encder which was fine. Phew! Very very relieved. I had looked at the previous forum and it hadn;t helped so I was quite worried. Thanks for your tips - using encoder to convert from mts to mp4 worked for me.