The protesters raised national flags as they occupied the footpath and a stretch of Sathon Road outside the embassy chanting "Min Aung Hlaing. Get out!" Some had also brought pictures of Aung San Suu Kyi or banners saying "Help us. Stop Crime" while others raised three fingers as a protest gesture.
Myat Mon Kyaw, 30, a Myanmar democracy activist who has lived in Thailand for six months said she had been devastated by the news of the four executions.
"I was very sad and angry. I cried a lot yesterday," she said.
Yao, 28, who has lived in Thailand for 18 years and joined the protest with his wife and seven-month-old daughter, said that the killings were unacceptable.
"I think no country does such things to their own people. This is a heartbreaking situation, especially as their family members were not informed until after they had already passed away. It is so bad that the family members were not given a chance to see their faces one last time," he said.
He said that if the Thai government was to offer any help, they would ask for assistance in returning Aung San Suu Kyi to a position of authority.
"Only our Suu Kyi can rescue us from this turmoil. Myanmar is dying," he concluded.
Anekchai Rueangrattanakorn, a Burmese Studies PhD graduate from Chulalongkorn University, and an observer of the protest, said that these were the first executions carried out by the state since the 1980s.
"The Thai government must abide by the international norm of sovereignty but also make clear it will not ignore continuing human rights violations by the Tatmadaw in Myanmar," he said.