"thousands of duplicate photos on iPhone", the Photos app on Mac indicates

I connected the iPhone to the Mac and opened Photos app on the Mac. There were thousands of photos on iPhone and I imported them and checked the box "Delete items after import". Near the end of import, the Photos app for Mac version 3.00 crashed. After I re-opened the Photos app for Mac, there are thousands of photos "Already imported".

Should I delete/remove them from my iPhone? How?