  The generation of highly charged Xe$^{q+}$ ions up to {$q=24$} is observed in
Xe clusters embedded in helium nanodroplets and exposed to intense femtosecond
laser pulses ($\lambda$=800 nm). Laser intensity resolved measurements show
that the high-$q$ ion generation starts at an unexpectedly low threshold
intensity of about {10$^{14}$ W/cm$^{2}$}. Above threshold, the Xe ion charge
spectrum saturates quickly and changes only weakly for higher laser
intensities. Good agreement between these observations and a molecular dynamics
analysis allows us to identify the mechanisms responsible for the highly
charged ion production and the surprising intensity threshold behavior of the
ionization process.
