About 4.4 million hadronic decays of Z bosons, recorded by the OPAL detector at LEP at a centre-of-mass energy of around sqrt(s) = 91.2 GeV, are used to determine the mean charged particle multiplicities for the three light quark flavours. Events from primary u, d, and s quarks are tagged by selecting characteristic particles which carry a large fraction of the beam energy. The charged particle multiplicities are measured in the hemispheres opposite to these particles. An unfolding procedure is

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... applied to obtain these multiplicities for each primary light quark flavour. This yields = 17.77 +- 0.51 +0.86 -1.20, = 21.44 +- 0.63 +1.46 -1.17, = 20.02 +- 0.13 +0.39 -0.37, where statistical and systematic errors are given. The results for and are almost fully statistically anti-correlated. Within the errors the result is consistent with the flavour independence of the strong interaction for the particle multiplicities in events from the light up, down, and strange quarks.