Based on research conducted between May and August 2018 by Human Rights Watch and the National Coalition for Human Rights Defenders, the report documents cases of harassment and intimidation against at least 35 activists by police or military and other government officials.

"'They Just Want to Silence Us': Abuses Against Environmental Activists at Kenya's Coast Region" describes obstacles activists face in voicing their concerns about the impacts of a longstanding regional infrastructure project known as LAPSSET, the Lamu Port-South Sudan-Ethiopia Transport corridor.

LAPSSET aims to open up a transport corridor from the tiny town of Lamu, which sits on an island off the central Kenyan coast, across northern Kenya. The mega-project involves the construction of a railway, a highway and three international airports as well as a crude oil pipeline, an oil refinery and three resort cities. The idea behind it is to open up northern Kenya and to attract more trade to the country from its landlocked neighbors of South Sudan, Ethiopia, and Uganda.

Lamu locals complain of being in the dark about the LAPSSET plans

The LAPPSET project also includes the construction of a a 32-berth port in Lamu and a coal-fired power plant some 20 km away.

The town, with its narrow, winding streets and stone buildings, is among the oldest and best-preserved Swahili settlement in East Africa and is also a UNESCO World Heritage site.

Read more: Pollution puts Lamu Old Town's World Heritage status at risk

Local communities in and around Lamu have become increasingly worried about how the project – especially the power plant and the port – will affect health, livelihoods and the environment.

Silencing those speaking out

According to the 69-page report, police have arbitrarily arrested or detained people in connection with their activism. Security forces have also broken up protests, restricted public meetings and threatened activists with various charges.

For example, according to the report, in May 2018 police arrested two activists during a peaceful protest in Lamu against the government's decision to proceed with construction of the power plant. Police held the activists at Lamu police station for six hours for participating in an "illegal assembly" before releasing them without charge.

Local fisherman Somo Mohamed is involved in Save Lamu, a local coalition of groups pushing for responsible development in Lamu. He said he had witnessed these arbitrary arrests firsthand.

With many fishing channels closed off because of ongoing dredging for the construction of Lamu port, traditional fishermen are worried about their livelihoods

"All our leaders from Save Lamu, who are all environmentalists, were arrested. Some were taken to the capital Nairobi. They were threatened and files with crucial evidence were confiscated in a move to intimidate them," he told DW.

He said the authorities don't want to face up to their failure to address the environmental and social consequences of LAPSETT.

"Since the start of LAPSSET, it has affected the lives of many fishers because the project takes place in our fishing grounds, and also it affects the mangroves that were breeding grounds for our fish," Mohamed said.

Loss of traditional fishing and land use

Communities are also upset about the inadequate compensation for land acquired by the projects.

Abdirahman Aboud, a farmer with fields outside of Lamu town, started protesting against LAPSSET after losing his land to the project. He has yet to receive compensation.

"I had ten acres on which I would plant cashew nuts, simsim [sesame] and maize," Aboud told DW at the report's launch in Nairobi.

"Upon harvest, I'd get food, sell some and have enough left over to educate my kids. I am now being forced to abandon my place, where do I go?"

Locals have been protesting aspects of the LAPSSET project for years

We have not opposed LAPSSET but the way LAPSSET is being brought to us as it will have serious consequences for Lamu residents."

Otsieno Namwaya, Africa researcher at Human Rights Watch, said at the press conference in Nairobi that silencing activists wouldn't resolve the concerns over whether the project is going to harm the environment and the people living there.

"The Kenyan government needs to urgently investigate the reports of harassment and intimidation of environmental activists in Lamu County and begin to protect and respect the rights of activists doing environmental work around LAPSSET."