Thai authorities arrested a group of activists wanted for attempting to demonstrate against the military last month, police said on Thursday, the latest arrest of dissidents in the junta-ruled country. Soldiers detained one student activist from the New Democracy opposition group late on Wednesday. Police arrested a further three members of the group on Thursday. A Bangkok military court later released the students, saying there was no reason to detain them because the punishment for defying a junta ban on protests was negligible. "There was no point to detain them," said Anon Numpa, a lawyer for the activists. They were the latest arrests by the army, which took power in a May 2014 coup and has since curbed basic freedoms and cracked down on critics. The junta, known as the National Council for Peace and Order, has defended the need to curb criticism at a politically sensitive time for the country. Sirawith Seritiwat, a student leader, said he was whisked away from a university campus north of Bangkok on Wednesday. He and the three other activists detained on Thursday are wanted by police for attempting to protest against alleged corruption in an army-built park. In a video taken at a police station, Sirawith said he was blindfolded and dragged through grass by authorities before being kicked and hit. Colonel Winthai Suvaree, a spokesman for the junta, denied authorities mistreated Sirawith. The other three activists were arrested at a police station where they were protesting against Sirawith's abduction. Chonthicha Jangrew, one of the three activists, said in a clip posted on Facebook that the junta was trying to silence those who disagree with it. Prime Minister Prayuth Chan-ocha said activists must abide by the law. "They have to learn to respect the law instead of claiming democracy and human rights," Prayuth told reporters. Police and soldiers last month temporarily detained dozens of students trying to protest against alleged army corruption involving the multi-million-dollar Rajabhakti Park, built in the seaside resort town of Hua Hin south of Bangkok. A defense ministry team looking into allegations of corruption at the park said last month it had found financial irregularities in the project but had no authority to investigate wrongdoing. The park, a sprawling concrete plaza showcasing seven giant bronze statues of former Thai kings, has been at the center of graft allegations by some Thai media and opposition groups, including irregularities in fundraising events and lack of fiscal transparency.