  Variability studies of active galactic nuclei are a powerful diagnostic tool
in understanding the physical processes occurring in disk-jet regions,
unresolved by direct imaging with currently available techniques. Here, we
report the first attempt to systematically characterize intra-night optical
variability (INOV) for a sample of seven apparently radio-quiet narrow-line
Seyfert 1 galaxies (RQNLSy1s) that had shown recurring flaring at 37 GHz in the
radio observations at Metsahovi Radio Observatory (MRO), indicating the
presence of relativistic jets in them, but no evidence for relativistic jets in
the recent radio observations of Karl G. Jansky Very Large Array (JVLA) at 1.6,
5.2, and 9.0 GHz. We have conducted a total of 28 intra-night sessions, each
lasting $\geq$ 3 hrs for this sample, resulting in an INOV duty cycle
($\overline{DC} ~\sim$20%) similar to that reported for $\gamma$-ray-NLSy1s (DC
$\sim$25% - 30%), that display blazar-like INOV. This in turn infers the
presence of relativistic jet in our sample sources. Thus, it appears that even
lower-mass (M$_{BH} \sim$10$^{6}$ M$_{\odot}$) RQNLSy1 galaxies can maintain
blazar-like activities. However, we note that the magnetic reconnection in the
magnetosphere of the black hole can also be a viable mechanism to give rise to
the INOV from these sources.
