MEXICO CITY (AP) -- The Popocatepetl Volcano near Mexico City let
                  off steam Friday and showed a slight increase in seismic activity, the
                  National Center for Disaster Prevention reported.

                  Authorities said the "yellow alert" signaling caution remained in effect and
                  urged people to keep at least 4 1/2 miles (7 kms) away from the crater, the
                  Notimex news agency said.

                  The National System for Civil Protection said the volcano had emitted
                  several small "exhalations" which sent up steam, gas and small amounts of
                  ash. One burst early Friday sent up a vapor plume some 2,000 feet (600
                  meters) above the volcano's peak.

                  The 18,000-foot volcano is located just 50 miles (80 kms) southeast of
                  Mexico City.

                  Popocatepetl has been spitting vapor, ash and rock intermittently since
                  December 1994, after lying largely dormant since 1927. Some 300,000
                  people live on its slopes and tens of millions live within view of it.