Mr Somchai, the commissioner in charge of election administration, said a total of 34 parties showed up on the first day of party-list registration, which remains open until Friday.
Of the 34 parties, only nine managed to submit their applications inside the Thailand-Japan sports complex at Din Daeng. Other parties were not able to get inside the premises because of the protest outside.
He said 24 parties had filed complaints with Din Daeng police station and another with the Crime Suppression Division.
Mr Somchai said the registration of the parties has not been completed until the EC has examined and accepted their documents.
The EC has not yet fixed the date and time for the parties to draw party numbers for the ballot sheets.
He denied as untrue a report that the EC had notified the Pheu Thai Party that the date for the draw of party numbers had been set for tomorrow.
The parties which had filed a police complaint were still required to formally submit their applications to the EC, he said.
The EC has not changed the venue for the registration and the draw of party numbers, Mr Somchai said.