Try to find this martial arts movie ?

All i can really remember is that its about 3 kids who i think are
brothers and at the end of the film they are getting chased by the
bad-guys(could be loads or just a few) and they end up in like an
amusment park or something, theres one part where one of the badguys
is in the open and the kids turn on a massive wave of water and take
him out, i think the youngest kid is like less than 10 and the oldest
is a teenager

its all about them being good at karate and trying to escape the bad
guys (i think)

sorry i cant remember much i think it was made the 90's but i have no
idea
Also it might have been part of a trilogy or quadrilogy or a sequal