The protest ends peacefully, with authorities promising a written statement, sources say.
Xie Yang's lawyers, who exposed details of his torture, are replaced with a government-appointed attorney.
Analysts say access to information about the standoff helped restrain the government.
President Xi Jinping promises to stay in regular contact with his U.S. counterpart Donald Trump amid a "rapidly changing international situation."
Last 19 hostages handed over after negotiations in which Hanoi's mayor vows to investigate farmers' complaints about land spat.
Vuthy Huot rejects assertions that he blended in with a group of opposition party officials to improperly access Prey Sar Prison on April 19.
Nineteen police officers and officials remain held amid the ongoing standoff over land.
Seven members of three families take guards' guns, throw magazines in Tumen River before fleeing on April 15.
Former soldier Oeuth Ang says his prison term for murdering Kem Ley does not offer an opportunity for him to reform himself.