  Major outbursts have been observed from the well-known high-energy peaked
blazar Markarian 501 since its discovery in 1996. Especially, two episodes of
very high energy gamma-ray flaring events during May-July 2005 and June 2012
are of special significance, when the source exhibited extreme HBL-like
behavior. The successful standard photohadronic model seems inadequate to
explain these extraneous behaviors. We propose a two-zone photohadronic
scenario to overcome this problem. In this picture, the low energy regime
(zone-1) of the spectrum follows the standard photohadronic interpretation,
while the high energy regime (zone-2) of the spectrum is new, with a spectral
index $\delta_2\geq 3.1$, which is solely due to the extreme nature of the
flaring event. We also estimate the bulk Lorentz factor corresponding to these
extreme flaring events. By analyzing many flaring events before and after these
extreme events we argue that the extreme HBL-like events are transient and may
repeat in future.
