Britain's King Charles and Queen Camilla began the second day of a state visit to Kenya on Wednesday as survivors of colonial-era abuses criticised his failure to issue a full apology or propose reparations.

At a state dinner on Tuesday Charles expressed his "deepest regret" for what he called abhorrent and unjustifiable acts of violence committed against Kenyans during the country's independence struggle.

President William Ruto commended the monarch's first step toward going beyond the "tentative and equivocal half-measures of past years", but said much remained to be done.

During the 1952-1960 Mau Mau revolt in central Kenya, some 90 000 Kenyans were killed or maimed and 160 000 detained, the Kenya Human Rights Commission (KHRC) has estimated.

British colonialists also committed gross human rights violations, including land expropriation, killings, torture and sexual violence, against hundreds of thousands of people in western Kenya over decades, UN investigators have said.

Charles' visit comes at a time when former colonies are demanding that Britain do more to recognise the abuses of its colonial past. Some - notably Barbados and Jamaica - have been re-evaluating their ties to the monarchy.

Britain agreed to a 20-million pound out-of-court settlement in 2013 to more than 5 200 survivors of abuses during the Mau Mau conflict, but it has refused to issue an apology and has rebuffed claims by other communities.

Britain's High Commissioner to Kenya, Neil Wigan, told a local radio station last week that an apology would take his country into "difficult legal territory".

"Acknowledgement alone is not enough," said David Ngasura, a historian from the Talai clan in western Kenya, whose members were forced from their land in the 1930s and sent to detention camps.

Today, much of that land belongs to multinational tea companies.

"I am yet to hear him about compensation and reparations by the British government to the victims of historical injustices meted by the British colonial government."

Kipchoge araap Chomu, the great-grandson of King Koitalel Arap Samoei, who led a decade-long rebellion by the Nandi people before he was killed by a British colonel in 1905, said Charles' speech fell short of his hopes for an apology, reparations and the return of his ancestor's remains.

"(Charles) just beat around the bush, went round, round saying 'we recognise the pain, we can't change the past'," Chomu said.

Chomu suggested Britain follow the example of Germany, which has apologised for its slaughter of tribespeople in Namibia more than a century ago and agreed to fund projects worth over a billion euros.

On Wednesday morning, Charles and Camilla visited a cemetery for veterans of World War Two. They awarded four veterans, who fought alongside the British, medals to replace ones they had disposed of during the Mau Mau uprising.