Kenya's former Chief Justice David Maraga has been arrested while protesting against, among other things, what activists are alleging is a plan to build a car park on protected land belonging to a wildlife sanctuary in the capital, Nairobi.

He was among a group of demonstrators who were marching along a road running close to the Nairobi National Park.

The 117-sq-km (45-sq-mile) site is a popular conservation area and tourist spot within Nairobi.

The Kenya Wildlife Service (KWS), which runs the park, is accused of giving a portion of the land to a neighbouring convention centre as well as planning to build a large new animal orphanage within the site. The KWS has vigorously defended its plans. 

It says the relocated and expanded orphanage will improve animal welfare and veterinary training, as well as allow for a better visitor experience. 

It will occupy an 89-acre site within the park - 0.31% of its total area, according to a KWS official quoted by the Star newspaper.

Social media videos show police breaking up Monday's protest and detaining a group of demonstrators who were filmed sitting in the middle of a two-lane highway.

Maraga, dressed in the colours of his United Green Movement party, can be seen being helped into the back of a lorry as people around him shout: "Long live the park."

The former chief justice, who hopes to run for president in the 2027 election, was arrested along with nine others. He has since been released but is refusing to leave the police station until the other activists have been freed.

The police have not released an official statement about the arrests.

Posting on X about the protest and his detention Maraga said he was held with "fellow patriotic Kenyans" who wanted to present a petition to KWS against the construction of a car park for 1,300 vehicles.

"Our national heritage and environment must be safeguarded from greed and unnecessary destruction without public participation," he added.

The KWS has not commented on the allegation about the car park but said that the public had been consulted about the plan to constrict a new orphanage.

Human rights group Amnesty International has "strongly" condemned the arrests of "peaceful protesters" following what it called a "violent dispersal".

"The use of force against citizens exercising their constitutional rights to peaceful assembly, expression, and public participation is unacceptable," it said in a joint statement with environmental groups.

Signatories included Greenpeace Africa, Friends of Nairobi National Park and The Green Belt Movement.