Colombia expressed concern early on Wednesday after revelations the United States had spied on the Andean nation, its closest military ally in Latin America, and called for an explanation. In a brief statement at midnight, Colombia's foreign ministry said it "registered its concern" that there had been an "unauthorised data collection programme" and asked that the US government give an account of its actions through its embassy in Bogota. A leading Brazilian newspaper reported on Tuesday that the US National Security Agency targeted most Latin American countries with spying programmes that monitored internet traffic, especially in Colombia, Venezuela, Brazil and Mexico.