  AIMS: We present a weak lensing search of galaxy clusters in the 4 deg2 of
the CFHT Legacy Survey Deep. This work aims at building a mass-selected sample
of clusters. METHODS: We use the deep i' band images to perform weak lensing
mass reconstructions and to identify high convergence peaks. Thanks to the
availability of deep ugriz exposures, sources are selected from their
photometric redshifts. We also use lensing tomography to derive an estimate of
the lens redshift. After considering the raw statistics of peaks we check
whether they can be associated to a clear optical counterpart or to published
X-ray selected clusters. RESULTS: Among the 14 peaks found above a
signal-to-noise detection threshold nu=3.5, eight are secure detections with
estimated redshift 0.15<zl<0.6 and a velocity dispersion 450<sigma\_v<600 km/s.
This low mass range is accessible thanks to the high density of background
sources. We also use photometric redshifts of sources to test the effect of
contamination by source-lens clustering for clusters detection. This latter
turns out to play a minor role in our cluster sample. We study the intersection
between the shear-selected clusters and XMM/LSS X-ray clusters in the D1 field.
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