  We report the discovery of high velocity candidates among RR~Lyrae stars
found in the Milky Way halo. We identified 9 RR~Lyrae stars with Galactocentric
velocities exceeding the local escape velocity based on the assumed Galaxy
potential. Based on close examination of their orbits', we ruled out their
ejection location in the Milky Way disk and bulge. The spatial distribution
revealed that seven out of 9 pulsators overlap with the position of the
Sagittarius stellar stream. Two out of these seven RR~Lyrae stars can be
tentatively linked to the Sagittarius dwarf spheroidal galaxy on the basis of
their orbits. Focusing on the high-velocity tail of the RR~Lyrae velocity
distribution we estimate the escape velocity in the Solar neighborhood to be
$v_{\rm esc}=512^{+94}_{-37}$\,km\,s$^{-1}$~($4$ to $12$\,kpc), and beyond the
Solar neighborhood as $v_{\rm esc}=436^{+44}_{-22}$\,km\,s$^{-1}$~and $v_{\rm
esc}=393^{+53}_{-26}$\,km\,s$^{-1}$~(for distances between $12$ to $20$\,kpc
and $20$ to $28$\,kpc), respectively. We utilized three escape velocity
estimates together with the local circular velocity to estimate the Milky Way
mass. The resulting measurement $M_{\rm 200}=0.83^{+0.29}_{-0.16} \cdot
10^{12}$\,M$_{\odot}$ falls on the lower end of the current Milky Way mass
estimates, but once corrected for the likely bias in the escape velocity
(approximately $10$ percent increase of the escape velocity), our mass estimate
yields $M_{\rm 200}=1.26^{+0.40}_{-0.22} \cdot 10^{12}$\,M$_{\odot}$, which is
in agreement with estimates based on different diagnostics of the Milky Way
mass. The MW mass within $20$\,kpc then corresponds to $M_{\rm MW} \left(r <
20\,\text{kpc} \right)=1.9^{+0.2}_{-0.1} \times 10^{11}$\,M$_{\odot}$ without
correction for bias, and $M_{\rm MW} \left(r < 20\,\text{kpc}
\right)=2.1^{+0.2}_{-0.1} \times 10^{11}$\,M$_{\odot}$ corrected for a likely
offset in escape velocities.
