Thousands of Albanians have taken to the streets of Tirana to protest against a plan by a company linked to President Donald Trump's son-in-law to build a luxury resort in an environmentally sensitive area.

Jared Kushner's investment firm Affinity Partners is involved in the $1.6 billion project on an undeveloped stretch of coastline that lies near the Vjosa-Narta protected area, a wetland home to flamingos, seals and sea turtle nesting sites in the south.

Environmentalists oppose the project, which they say would affect several square kilometers of pristine beaches and thousands of flamingos that nest and pass through nearby areas each year.

Ornithologist Ledi Selgjekaj said more than 1% of the global population of flamingos is in Albania.

"Of course, it's very important to have investments in the country. It's very important for the economy, but you have to choose very wisely where to build it. There is a reason why this area is called a protected area," she said.

Groundwork and the arrival of heavy machinery at the site triggered local protests last week which were followed by large street demonstrations in Tirana.

'Albania is not for sale' 

Locals rushed to the area to check the situation on Friday as police patrolled, hours after protesters gathered outside the office of Albania's Prime Minister Edi Rama, holding pink inflatable flamingos and chanting "revolution" and "stop the project". A placard read: "Edi Rama, resign."

"Albania is not for sale. Albania belongs to the Albanian people and we decide what we want to do here. It's not that some corrupt politicians who run Albania can decide what they can do with our property, with the Albanian heritage, the natural heritage, a cultural heritage," said Lindita Komani, a writer who joined the protests.

On Friday, there was no sign of the builders or heavy machinery that had been preparing the ground in recent days at the site of the planned resort.

Rama has defended the project. Developers have said their focus will be "responsible stewardship and environmental enhancement."

Albania's Economy and Innovation Minister Delina Ibrahimaj said on Thursday that environmental impact assessments are being drafted for the proposed investment which would have to comply fully with environmental legislation and safeguard the local habitat.

European environmental directives and Albanian law provide legal guarantees against projects that could harm the protected lagoon and surrounding habitats, she was quoted as saying by Albania's state news agency ATA.