The protesters, led by co-leaders of the Songkhla People's Democratic Reform Committee (PDRC), demanded the EC immediately halt all registration proceedings.
The tense situation eased after the provincial election officials agreed to comply with their demand today.
Protesters were still gathering at the stadium, planning to wait and see whether atempts would be made to reopen registration tomorrow.
It was reported that candidates of Pheu Thai and Bhumjaithai parties showed up at the centre planning to register.
Constituency candidate registration offically ends on Jan 1.