During the prime minister's first visit to the Northeast, five student activists yesterday stole the show by making their way to the front of the stage and launching a protest against the coup and its leader, General Prayut Chan-o-cha.
The young men, students from Khon Kaen University's faculty of law, managed to sneak past the tight security at Khon Kaen's Provincial Hall, where Prayut was delivering a speech. He was there to oversee the release of a caravan of water trucks to help drought-hit areas.
The five students ran to the stage, took their shirts off to reveal black T-shirts with white lettering that read "No to the coup" in Thai when the young men stood side by side.
The students also held up their arms in a three-finger salute - a symbolic anti-coup gesture - at the PM.
The five were immediately arrested and ushered out of the hall. They were later taken to Khon Kaen's provincial police command for questioning and then to the 23rd Army Circle in the province for detention, as martial law is still in effect.
The authorities released the students temporarily in the evening, even though the young men refused to sign a document promising not to protest again in violation of the junta's orders, a source said. Instead, they chose to fight the case in court.
The five men were also told to report to the authorities this afternoon, along with their parents, to possibly "adjust their attitude".
The unexpected interruption took Prayut briefly by surprise, but he later managed to smile. He joked that he thought the students' protest was part of a stage show, adding with a smile: "Who else will protest next? You can do it now so I can resume my speech."
His remark was greeted with applause. Prayut then completed his speech and proceeded with the ceremony.
This is the first time that Prayut has witnessed the dissatisfaction in some people for this unelected government that was formed after the coup, which he led almost six months ago while serving as Army chief.
When speaking to reporters later, the PM said he was not discouraged by what had happened in Khon Kaen yesterday.
After completing his trip to the Northeast, Prayut said he would travel to other parts of the country, including the North and the deep South.
When asked if he would dare to go to the North, which is also considered a Pheu Thai stronghold, Prayut replied: "Why not? Do I need to fight against anybody? I won't be fighting with anyone."
The students were identified as Jatupat Boonpattararaksa, Phayu Boonsopon, Vitchakorn Anuchon, Jetsarit Namkote, and Wasan Seksit.
The five students, part of a group of activists called "Dao Din" (Earth's Star), have been working with environment activists and often stage protests against projects deemed to be harmful, mostly in the Northeast.
Yesterday's event led to questions about Prayut's safety. Political activist Suriyasai Katasila wondered if there were any mistakes made by the security detail or if the security flaw was intentional to embarrass Prayut.
Separately, early yesterday leaflets were found outside Khon Kaen's Provincial Hall and on some main roads in the city area carrying the message: "Northeasterners do not welcome the dictator."
Meanwhile, Army chief General Udomdej Sitabutr, who is also deputy defence minister, said he thought it was inappropriate to protest against the premier when he was visiting locals out of care.
The Northeast is considered a stronghold of Pheu Thai, which led the government that was deposed on May 22.