Bulgarian police have arrested three people for illegally trafficking human kidneys to transplant patients in neighboring Turkey, the interior ministry said Wednesday.

Police detained two men and a woman in the eastern town of Shumen for transporting at least six Bulgarians to a private Istanbul clinic where their kidneys were removed and sold to waiting transplant patients, the ministry said in a statement.

“It was found that the members of this group persuaded people to sell their organs,” the ministry said. If found guilty, the accused face up to 10 years in prison.

News agency BTA cited interior ministry Chief Secretary Boiko Borissov as saying the kidneys were sold for $2,500-$5,000 each, depending on blood type.