“I honour those who have been lost and encourage support for the survivors and the families of those affected.
“Those who work for Halo in Afghanistan face risks every day to remove the lasting – and still deadly – scars of war and conflict.”
The Duke of Sussex highlighted the dangers charity workers put themselves through to make the world a better place and called on people to “stand in solidarity with humanitarian aid workers and the communities they serve”.
He added: “The men who were attacked come from the very communities in which they work. They joined Halo to protect and restore their country and their homes.
“As I understand it, the deminers who lost their lives were also protecting their friends.
“These workers put their lives on the line every day to make the world a safer place.
“This brutal act reminds us that we must stand in solidarity with humanitarian aid workers and the communities they serve.”
More than 100 men from local communities retreated to the camp after working in the minefields, when gunmen stormed the area.
The Halo Trust said the brutal attack was carried out by an unknown armed group shortly before 10pm local time.
An affiliate of so-called Islamic State has claimed it was behind the incident.
The Halo Trust was supported by Diana, Princess of Wales, and has had a close affiliation with Prince Harry.
More to follow