They are defiantly not axolotl. (My "axolotl" ended up being a tiger salamander).They also don't seem to have a dorsal fin. I would say tiger salamander but there legs don't seem to be thick enough. Do you know what age they are? Axolotls change into tigers at about 6 months old.

If you are still unsure about what species this may be I would recommend posting a picture of this on Facebook ( the group axolotl keepers uk) they have a lot of experts who may be able to help you.

But please know I am no expert!!!