Cant delete pictures off photos app on iPhone

So I took 4 pictures with my iPhone.

These were transferred automatically via photo stream to my mac.

On my mac I deleted them off the photos app.

Also I deleted them off the camera app on iPhone.

However these 4 pictures are still on my iPhone photos app and I cant delete them (no trash can)

Not had this problem before.

I have rebuilt my laptop photos library but can see a way to do this on iPhone.

Any idea how to remove these photos ?

thanks.

Just too add I have almost 8,200 pictures on my iPhone