Former Prime Minister VP Singh and Jan Morcha leader Raj Babbar were among around 100 people arrested at the Delhi-UP border on Saturday.
The arrest took place when they were proceeding towards Bhejera Khurd village to protest the land acquisition for Reliance Energy's power plant.
Singh, who has been spearheading a campaign against UP government's land acquisition for the company, was scheduled to plough the land at the site to protest the project.
The two leaders and former MP Bhola Singh, who were accompanied by 27 farmers, were detained on the border for violating prohibitory orders, District Magistrate MKS Sundram said.
Seventy others were arrested at the protest site.
The trio, who declined to go with the police, will be released after they submit a personal bond, he said.