  We report on the detection of sporadic, strong single pulses co-existing with
a periodic weak emission in the duration of weak mode of PSR B0826-34. The
intensities and durations of these pulses are comparable with that of the
sub-pulses in the strong mode, and these pulses are distributed within the
phase ranges of the main-pulse and interpulse of the strong-mode average
profile. These results suggest that there are most possibly sporadic, very
short timescale turn-on of strong-mode emission during the weak-mode state of
the pulsar. The emission features of the bursts of strong pulses of PSR
B0826-34 during its weak-mode state are similar to those of the rotating radio
transients (RRATs). PSR B0826-34 is the second pulsar known which oscillates
between pulsar-like and RRAT-like modes.
