DMX -- Accused in Gas Station Cash Grab

Rapper DMX is being accused of making an unwanted withdrawal at a gas station, but not from an ATM ... from some random guy!

A 21-year-old guy told police in Newark, NJ he encountered X early Sunday morning at an Exxon station. The guy told cops he had a brief convo with X -- about rap music -- when suddenly a member of X's entourage flashed a gun and demanded the guy's money.

For some reason, the alleged victim had $3,200 on him in cash, which he claims X grabbed before getting back into his car and speeding away.

So far no charges have been filed.