RIO DE JANEIRO, Brazil — Brazilian police confirm that suspected al-Qaida terrorist Khalid Shaikh Mohammed visited their country in the 1990s, and U.S. intelligence suggests that he may have hidden out in the region. Mohammed's visit — the first confirmed al-Qaida presence in South America — renews fears that Osama bin Laden's organization may have sleeper cells in South America. There have been numerous unconfirmed reports of al-Qaida training camps on Paraguay's border with Brazil. When he was apprehended in Pakistan on March 1, Mohammed was one of the world's most sought-after suspected terrorists. Dubbed the field general of al-Qaida,...