  Recent astrophysical transient Swift J1913.1+1946 is possibly associated with
the gamma-ray burst GRB 221009A at the redshift z=0.151. The transient was
accompanied by very high-energy gamma rays up to 18 TeV observed by LHAASO and
a photon-like air shower of 251 TeV detected by Carpet-2. These energetic gamma
rays cannot reach us from the claimed distance of the source because of the
pair production on cosmic background radiation. If the identification and
redshift measurements are correct, one would require new physics to explain the
data. One possibility invokes axion-like particles (ALPs) which mix with
photons but do not attenuate on the background radiation. Here we explore the
ALP parameter space and find that the ALP-photon mixing in the Milky Way, and
not in the intergalactic space, may help to explain the observations. However,
given the low Galactic latitude of the event, misidentification with a Galactic
transient remains an undiscarded explanation.
