have single entry PRC Business visa, do I need HK entry permit to stay at HK as tourist for 4 days?

I am from India. travelling to PRC for business. I have applied single entry PRC business M type will get soon. I am landing at HK on 20th June & then by air port bus going to Shenzhen . 1. Do I need HK VOA?
Same way on return, I am coming from Shanghai on 26th June to HK & staying 4 days as tourist & leaving HK on 29th. Again I need HK entry permit ?