Tens of thousands of people protested in the Albanian capital, Tirana, on Saturday in the largest demonstration since a campaign against the construction of a luxury resort linked to the family of U.S. President Donald Trump began.

The protest, held on the 35th day of the movement, was the biggest since demonstrations started in late May against a luxury hotel project associated with Trump's daughter, Ivanka, and her husband, Jared Kushner. The development is planned along the coast of a protected nature reserve in the Balkans.

Public anger over corruption in Albania has fueled opposition to the project, with protesters broadening their demands to include the resignation of Prime Minister Edi Rama.

The movement has been dubbed the "Pink Flamingo Revolution," after the nature reserve where the project is planned, a key migratory destination for pink flamingos.

Protesters argue that the $4.6 billion hotel project in the Zvernec area threatens the environment and a nearby lake that serves as a vital habitat for migratory birds.

The developers also plan to transform the uninhabited island of Sazan, once a secret communist military base, into a luxury tourist destination.

Protesters during their demonstration in central Tirana (AFP)

Earlier this week, protesters gathered for a second time outside Albania's parliament building, attempting to block lawmakers from entering. Riot police pushed them back, sparking clashes and the arrest of several demonstrators.

Police used tear gas, pepper spray, and water cannons to disperse the crowds after some protesters attempted to breach security lines. Authorities said 15 police officers were injured and taken to hospital for treatment, while 25 protesters were arrested.

On Saturday, the Albanian Helsinki Committee, a leading local human rights organization, said that "individual violence cannot justify the excessive use of force" by police.

Later that evening, demonstrators chanted, "Release the youth," in reference to 19 protesters who remained in police custody.

Protesters carried signs reading "Albania is not for sale" and "Repeal the Protected Areas Law," referring to legislation that enabled the government to fast-track the project.

Many also carried large pink flamingo models as they marched toward government headquarters in Tirana, along with a giant model of a concrete cake symbolizing Prime Minister Edi Rama's 62nd birthday on Saturday.

The march later moved toward a police station, where protesters demanded the release of the 19 detainees. Some demonstrators threw stones and smashed the station's windows, prompting police to use water cannons to disperse the crowd shortly before midnight.