A group of about 30 people gathered at the Pheu Thai Party head office on Saturday, calling for the government to withdraw all amnesty-related bills.
The group was led by Capt Songklod Chuenchuphol, a member of the Thai Patriots Network.
About 45 police were on hand to maintain order.
Capt Songklod said his group chose to gather in front of the Pheu Thai office because it was outside the areas under the Internal Security Act.
Discussing Prime Minister Yingluck Shinawatra's call for new reconciliation talks, Capt Songklod said it was only a time-buying tactic.