Palestinian activists climbed wooden ladders leaning against the West Bank security fence Friday, carefully spraypainting "My dear Palestinian brothers" - the first words of what they say will turn into a letter stretching over 1.6 miles (2.6 kilometers) long. The letter, composed by South African human rights activist Farid Esack, contends that Israel's treatment of Palestinians living under military rule is in some ways worse than what blacks suffered during the apartheid era in South Africa. Israel has vehemently rejected such comparisons. The activists hope the words, sprayed on a stretch of the wall north of Jerusalem, will highlight opposition to the barrier. Israel started building the fence, made up of electronic fences and concrete slabs, in 2002, following a wave of shooting and bombing attacks by Palestinian terrorists.