According to the Wikipedia's graph of electric field in a p-n junction, there is no electric field outside the deletion region and hence no minority charge carriers move into the other side. Also, the minority charge carriers which cause the drift current are swept off. So there are no more free charge carriers in the depletion region. Then the drift current will stop whereas the diffusion current will not. So how is the equilibrium maintained in a p-n junction ?
The free carriers leave behind charged atoms of opposite sign; they provide an electric field that balances the diffusion current. Specifically, as the electrons drift into the p-region positively charged atoms are created and similarly when holes are swept to the n-side negatively charged atoms are created. So an electric field is setup between these fixed charges that oppose the diffusion current.