  HESS J1809-193 is an unidentified TeV source discovered by the High Energy
Stereoscopic System and originally classified as a pulsar wind nebula (PWN)
candidate associated with the pulsar PSR J1809-1917. However, a recent study of
deep radio observations and the interstellar medium near the source has found
evidence for a hadronic scenario for the gamma-rays. Here, a detailed study of
the GeV emission in the region using data from the \emph{Fermi} LAT is
presented. The GeV emission has an extended morphology in the region of the TeV
emission and the overall spectrum can be accounted for by a cosmic ray
population having a simple power-law spectrum with energies extending up to 1
PeV. However, the spectrum at tens of TeV should be observed more deeply in the
future to confirm its hadronic nature, and other scenarios involving
combinations of leptonic and hadronic emission from several of the known
supernova remnants in the region cannot be ruled out. The nearby TeV source
HESS J1813-178, thought to be a PWN, is also studied in detail at GeV energies
and we find a region of significant emission which is much more extended than
the TeV emission and whose spectrum is softer than expected from a PWN but
similar to those seen in several star forming regions that are believed to
accelerate protons. There is marginal evidence for a GeV point source at the
location of the X-ray PWN, beside the extended emission.
