The EC is organising make-up elections in Phetchaburi, Rayong, Phetchabun, Samut Songkhram, and Samut Sakhon.
Somchai said the preparations for the elections had gone well and there had been no opposition.
Officials to man the polling stations had been recruited and problems had not been encountered in terms of the venues or equipping them with the necessary tools.
He said the EC had also received full support from security agencies and the Interior Ministry for the holding of the election.