We have used the VLBA at 5 GHz to observe all galaxies with nuclear radio flux densities above 3.5 mJy found in a VLA survey at 15 GHz of a sample of nearby LINER galaxies .
All galaxies were detected revealing high brightness temperature ( T _ { b } \gtrsim 10 ^ { 8 } K ) radio sources .
Free-free emission is unlikely since it greatly overpredicts the soft X-ray luminosities .
We infer the presence of AGN-like , non-thermal radio emission most likely powered by under-fed black holes .
Together with our VLA sample we estimate from our observations that at least half of LINER galaxies host genuine AGN .
We find no evidence for highly inverted radio cores as predicted in the ADAF model : the ( non-simultaneous ) spectral indices are on average around \alpha = 0.0 .
In the two brightest sources we detect some extended emission , which appears to originate in jets in at least one of these galaxies .
Together with the spectral indices this suggests that the nuclear emission at centimeter radio waves is largely dominated by emission from radio jets , very similar to the situation in more luminous AGN .
The energy released in these jets could be a significant fraction of the energy budget in the accretion flow .