Charles and his wife Queen Camilla are set to embark on Tuesday on a four-day trip to the East African nation, his first visit as king to a Commonwealth member.

“We call upon the King on behalf of the British government to issue an unconditional and unequivocal public apology (as opposed to the very cautious, self-preserving and protective statements of regrets) for the brutal and inhuman treatment inflicted on Kenyan citizens,” the non-governmental organisation KHRC said.

According to Buckingham Palace, Charles was expected to tackle “the more painful aspects” of the UK’s historic relationship with Kenya.

This would include the 1952-1960 “Emergency”, when colonial authorities clamped down on the Mau Mau guerrilla campaign against European settlers.

About 10,000 people – mainly from the Kikuyu community – were killed during the suppression of the uprising.

“His Majesty will take time during the visit to deepen his understanding of the wrongs suffered in this period by the people of Kenya,” the palace said this month.

The KHRC said the apology should cover the entire colonial period from 1895 to 1963.

“We further demand effective reparations for all the atrocities committed to the different groups in the country,” it said, urging President William Ruto to “prioritise this in his meetings” with Charles.

After a court case lasting several years, the UK agreed in 2013 to compensate more than 5,000 Kenyans who had suffered abuse during the Mau Mau revolt, in a deal worth nearly £20 million.

In Nairobi, Charles will meet entrepreneurs and young Kenyans and participate in a state banquet.

He will also visit a new museum dedicated to Kenya’s history and lay a wreath at the Tomb of the Unknown Warrior in Uhuru Gardens, where independence was declared in December 1963.

The royals will then travel to the coastal city of Mombasa, touring a nature reserve and meeting religious representatives.

Kenya is preparing to celebrate 60 years of independence from the UK.