In a belated action, authorities of Quang Ninh Province, home to Ha Long Bay, demanded Thursday that the bay’s management board stop two projects in its core zone.

The move followed several media reports saying the zone has been bombarded with illegal construction works.

Two projects to upgrade and innovate the piers for boats to dock at Tien Ong and Me Cung caves in the bay are part of a bigger project to preserve and promote the heritage values of the bay.

They were approved by the province and the Ministry of Culture, Sports and Tourism in December last year, but were yet to get an environmental impact assessment.

Pham Dinh Huynh, deputy head of Ha Long's management board, said it had already submitted the environmental impact assessments for the two projects, costing VND30 billion ($1.3 million) in total, to the environment ministry, but was yet to receive any response.

"As the stormy and rainy season is coming but the piers at the two caves are downgraded, posing a potential danger for tourists, the board decided to start work on the two projects," he said.

Aside from these two projects, Huynh conceded there were several others that were also illegal, including a 170-meter-long embankment built of stones and concrete linking to a pier at the Cay Chanh Islet.

An embankment running 170 meters along Cay Chanh Islet
in the core zone of Ha Long Bay. Photo by VnExpress/Minh Cuong

"Those projects had been under construction since 2016, and Ha Long has issued decisions to revoke them but so far that has changed nothing.

"We are making proposals to higher authorities to stop them," he said.

Ha Long Bay has an area of around 1,553 square kilometers (600 square miles), including 1,960–2,000 islets, most of which are limestone structures.

In 1994, the core zone of Ha Long Bay was listed as a World Heritage Site and listed for a second time in 2000.

The bay is a top attraction in Vietnam, helping Quang Ninh Province attract 5.2 million foreign visitors last year, up 22 percent from a year ago and accounting for one third of foreign visitors to Vietnam.

Following the tourism boom, Ha Long Bay has had to deal with serious pollution in recent years, with its docks usually littered with garbage, engine oil and carcasses of animals.