A museum documenting the 1989 Tiananmen Square massacre has reopened in Hong Kong after a three-year hiatus, marking the 30th anniversary of the bloody crackdown on a pro-democracy protest.

“The reopening of this June 4th Museum on the 30th anniversary is a clear demonstration of our commitment to uphold memory, pursue justice and hope for the future of our country,” Albert Ho, head of a group that operates the museum, said Friday, referring to the date the military crackdown is remembered by.

The museum showcases relics from the incident, including a helmet worn by Chinese student Wang Nan when he was shot in the head by troops, and a bullet fragment removed from another student, Zhang Jian, who recently died.

Other items on display include photographs, newspaper clippings and declassified government documents related to the incident.

The museum first opened in 2014 in a commercial building but was forced to close two years later amid legal disputes with the site’s owner. Its new location, also in a commercial building in the Mong Kok district of Kowloon, could face similar challenges from the building’s owner.

The museum is operated by the Hong Kong Alliance in Support of Patriotic Democratic Movements in China, which holds annual memorials for the hundreds of mainly student protesters who died after soldiers began the crackdown on the night of June 3, 1989, and later opened fire on protesters in Tiananmen Square.

“We cannot lose sight of the past and close eyes to injustice in the past, because if we did not remember the past, we would lose sight of the future,” Ho said. “We will continue … to call for vindication of the student movement and … to bring those responsible to justice.”

Cheung Wing-fai, a 60-year-old former teacher who was visiting the museum, called it “meaningful,” because Hong Kong is the only place in China to host such a site.

“I hope (the museum) will continue (operate) so that people who want to know history can come, no matter how differently people think of the crackdown,” he said.

Before the museum reopened, about 20 people had staged protests at the new site for days, calling for its expulsion on the grounds that it would draw too many visitors and become a disturbance to other proprietors in the building.

Ho said police are investigating after the museum was vandalized about two weeks before the reopening. He believes the attack was politically motivated.