Quito has been under an alert since Monday night to guard against an
                  eruption of the Guagua Pichincha volcano.

                  Houses, trees and cars in the capital's southern district were blanketed white
                  with silty ash spit up by the volcano during a brief eruption just before
                  midnight Tuesday.

                  "There was no explosion," geophysical scientist Darwin Villagomez said.

                  Many city residents in the affected areas walked the streets Wednesday
                  morning with their faces covered by surgical masks and handkerchiefs.

                  Officials have downplayed the danger to Quito in the face of a major
                  eruption.

                  The Pichincha volcano has two smaller cone peaks, Guagua Pichincha
                   and the inactive Rucu Pichincha.

                   Because Guagua Pichincha's crater faces away from Quito, any eruption
                   would burst north, west and south, sparing the capital city, authorities say.

                  Civil defense and military units started evacuations Tuesday of campesinos in
                  three villages vulnerable to lava flows on the northern, western and southern
                  slopes of the volcano.

                  Guagua Pichincha's last major eruption was in 1660, when it spewed ash for
                  nine days but killing no one, according to Spanish records.