salamader identification

[urd]

i have recently caught three salamanders, but as we have no salamanders native to england i was hoping someone on here could help me identify them. they are common pets over here so my guess is they were released or escaped.

the largest is about 4 inches including tail. they are very dark brown/black and have white warts/spots down their sides. there bellies are very like fire bellied toads but are yellow and black instead of red and black.

thanks for any replies,
nick