(TMZ) A battle was lost, but the war's not over ... Al Sharpton says he WILL NOT REST until justice is served for Trayvon Martin's death -- after yesterday's not guilty verdict for the man who pulled the trigger.
Our photog spotted Rev. Sharpton at LaGuardia Airport Sunday -- and asked if he was disappointed that 6 jurors acquitted Zimmerman of all charges. His answer ... a resounding YES.
However, Al says this is not the end ... "We always had a plan B. We now go to the Justice Department seeking civil rights charges." He adds, "We're not gonna stop until we get justice."