  Under a perfect periodic potential, the electric current density induced by a
constant electric field may exhibit nontrivial oscillations, so-called Bloch
oscillations, with an amplitude that remains nonzero in the large system size
limit. Such oscillations have been well studied for nearly noninteracting
particles and observed in experiments. In this work, we revisit Bloch
oscillations in strongly interacting systems. By analyzing the spin-1/2 XXZ
chain, which can be mapped to a model of spinless electrons, we demonstrate
that the current density at special values of the anisotropy parameter
$\Delta=-\cos(\pi/p)$ ($p=3,4,5,\cdots$) in the ferromagnetic gapless regime
behaves qualitatively the same as in the noninteracting case ($\Delta=0$) even
in the weak electric field limit. When $\Delta$ deviates from these values, the
amplitude of the oscillation under a weak electric field is suppressed by a
factor of the system size. We estimate the strength of the electric field
required to observe such a behavior using the Landau--Zener formula.
