  We report discovery of several energetic radio bursts at 34 MHz, using the
Gauribidanur radio telescope. The radio bursts exhibit two important properties
associated with the propagation of astronomical signals through the
interstellar medium: (i) frequency dependent dispersive delays across the
observing bandwidth, and (ii) Faraday rotation of the plane of linear
polarization. These bursts sample a range of dispersion measures (DM;
1.4--3.6$~{\rm pc}~{\rm cm}^{-3}$), and show DM-variation at timescales of the
order of a minute. Using groups of bursts having a consistent DM, we show that
the bursts have originated from the radio-quiet gamma-ray pulsar Geminga.
Detection of these bursts supports the existence of occasional radio emission
from Geminga. The rare occurrence of these bursts, and the short timescale
variation in their DM (if really caused by the intervening medium or the pulsar
magnetosphere), might provide clues as to why the pulsar has not been detected
in earlier sensitive searches. We present details of the observations and
search procedure used to discover these bursts, a detailed analysis of their
properties, and evidences of these bursts being associated with Geminga pulsar,
and discuss briefly the possible emission mechanism of these bursts.
