Also, are you absolutely sure that these people were under 18?

I say that because caucasians look so much older than asians or mediterraneans. A 20 y/o philippina can easily look like a teenager.

I remember when I was in London, from 25 years old to 27, I had to show my ID to the doormans in the clubs even thought my friends could get in withouth any problems! They believed I was under 18? Shocking.