  HESS J1809-193 is an extended TeV gamma-ray source in the Galactic Plane.
Multiwavelength observations of the HESS J1809-193 field reveal a complex
picture. We present results from three CXO and two Suzaku observations of a
region in the northeastern outskirts of HESS J1809-193, where enhanced TeV
emission has been reported. Our analysis also includes GeV gamma-ray and radio
data. One of the X-ray sources in the field is the X-ray binary XTE J1810-189,
for which we present the outburst history from multiple observatories and
confirm that XTE J1810-189 is a strongly variable type I X-ray burster, which
can hardly produce TeV emission. We investigate whether there is any connection
between the possible TeV extension of HESS J1809-193 and the sources seen at
lower energies. We find that another X-ray binary candidate, Suzaku J1811-1900,
and a radio supernova remnant, SNR G11.4-0.1, can hardly be responsible for the
putative TeV emission. Our multiwavelength classification of fainter X-ray
point sources also does not produce a plausible candidate. We conclude that the
northeast extension of HESS J1809-193, if confirmed by deeper observations, can
be considered as a dark accelerator - a TeV source without visible counterpart
at lower energies.
