Demonstrators with red bandanas tied around their heads waved placards outside the pale walls of the Myanmar embassy as they marked two years since the military ousted democracy icon Aung San Suu Kyi's government.

Since the putsch a crackdown on dissent has seen violence flare around the nation as opposition groups take up arms against the junta.

"This morning I woke up, my eyes swollen, totally angry," said Zai, 30, who wanted only his first name used after fleeing Myanmar's commercial capital Yangon a year ago.

"We are against the military and all their supporters," he added, anti-junta slogans pinned across his jacket.

"They are targeting all people, especially the young. I would not be safe there" because he used to work in the media, he said.

Thai police stood by watching the roughly 400 demonstrators, only intervening to shepherd them away from traffic.

Rappers and a small theatrical group helped hype up the crowd with anti-junta slogans and a three-fingered salute that has become a symbol of anti-coup demonstrations.

Supporters hung over railings with smiling children hoisted on their shoulders next to placards bearing framed photos of Suu Kyi.

The scene was a far cry from the tightly controlled streets of Myanmar that Zai has left behind, he said.

One of his university classmates was jailed after protesting, he added, disappearing into Myanmar's prison system for a five-year sentence.

"When I see something loud... I am scared," Zai said. "It's a kind of trauma. It's not just me, everyone is scared."

As the junta attempts to tighten control, violence between the military and anti-junta groups including ethnic rebels has increased.

More than 2,900 people have been killed in the military's crackdown with around 18,000 arrested, according to a local monitoring group.

"We don't want anything from them (the military), we just demand our mother back," said Kywa Tayzar, using an honorific often used to describe Suu Kyi.

Another protester, 25-year-old factory worker Kyaw Zin, his orange-dyed hair bright in the sunlight, held signs in English saying "we need to be the last generation under dictatorship".

"I have hope," he said.