Ghana held a ceremony on Sunday to mark the 200th anniversary at a white-washed former slave fort in Elmina, a port that dispatched hundreds of thousands of Africans to a life of subjugation in the New World.

More than 10 million Africans – some estimates say up to 60 million – were sent on slave ships. Many perished on the voyage or on disease-infested plantations.

“We have seen the manipulation, the impoverishment of Africa ... That is testament to the effects of slavery,” South African jazz icon Hugh Masekela told a news conference. “There is no price, no price for what has been done.”

Portugal built sub-Saharan Africa’s first permanent slave trading post at Elmina in 1492.

It passed into English hands and by the 18th century shipped tens of thousands of Africans a year through “the door of no return” on to squalid slave ships bound for the Americas. “It was so bad the way they maltreated our forefathers, the way they chained them and imprisoned them for so many years,” said Anthony Kinful, 38, a storekeeper near the Elmina fort. “If I see white people now, I think badly of them.” After years of campaigning by anti-slavery activists like politician William Wilberforce, Britain banned the trade in slaves from Africa on March 25, 1807.

Britain did not outlaw slavery until 1833. The transatlantic trade continued under foreign flags for many years. A senior Church of England cleric called for British Prime Minister Tony Blair on Sunday to make a formal apology.

“A nation of this quality should have the sense of saying we are very sorry and we have to put the record straight,” Archbishop of York John Sentamu told the BBC.

When Ghana’s President John Kufuor visited London this month, Blair said Britain was sorry for the slave trade. But many Africans want more, including reparations.

The anniversary has raised awareness of modern-day forms of bondage, from illegal chattel slavery still practised in some nations in Africa’s dry Sahel belt, to mafias which traffic African girls as prostitutes to the West.

“The traffic in human beings is clearly not over,” said Ghanaian poet Kofi Anyi Doho. “There are no boats to anchor next to a slave fort but people are being forced into ... a form of enslavement all over the world.”

In neighbouring Sierra Leone, one of the world’s poorest countries originally founded as a haven for freed slaves, journalist Samuel Beckley said Africa was still suffering. “Slavery took away our strong men,” Beckley said at a church founded in 1808 by exiled Jamaican Maroons – slaves who revolted against British rule. “The economic potential of Africa was put in reverse gear ... The only way to make amends is reparations.”

Britain’s first black cabinet minister Baroness Valerie Amos, herself a descendant of slaves who was born in Guyana, joined Masekela and Jamaican-born reggae dub poet Linton Kwesi Johnson at a ceremony later .