BMTC Buses with Bengaluru board on M'lore - B'lore HIghway

I was travelling by KSRTC day bus to M'luru from B'luru and noticed lots of BMTC buses (about 10 minute interval) with Bengaluru board going toward Bengaluru throughout my journey till Nelyadi after which I did not see any, so assuming it could starting at Dharmasthala. Any one has any information if this was a special buses or scheduled ones?