MEXICO CITY, Mexico (AP) -- Residents of many small towns at the base of Mexico's
                  Popocatepetl volcano stayed up until dawn Monday, fearing the mountain's overnight
                  rumblings were signs that a stronger eruption was brewing.

                  Officials have urged some 40,000 people living within six miles of the volcano to leave
                  the area, but most have ignored the pleas, preferring to stay behind to guard their
                  belongings and livestock.

                  About 10,000 people have fled, and buses were parked along roadsides waiting to shuttle
                  more people to shelters in safe areas. Interior Minister Santiago Creel said
                  authorities may force residents to evacuate if the situation becomes more
                  serious.

                  Scientists have warned that a dome of lava at the base of the 17,886-foot volcano is causing
                  pressure to build. That could trigger a strong eruption, throwing rocks and other debris for
                  miles.

                  The volcano, locally known as "Popo," sits 40 miles southeast of Mexico City and is often visible
                  from the second-largest city in the world.

                  Yet a major eruption would unlikely do more than dust the metropolitan area's 20 million residents
                  with ash. At higher risk are the small communities dotting the volcano's base.

                  The volcano was mostly stable on Monday after a night of low-level earthquakes
                  and rumblings that kept many nearby residents awake. Several packed their cars
                  with clothes and valuables, waiting to flee if an eruption happened.

                  People have grown accustomed to the vapor, ash and incandescent rock that the
                  volcano has been spewing intermittently for the past six years. Still, this week
                  has been one of its most active in two years.

                  Scientists are largely concerned by the volcano's unprecedented seismic activity.
                  Many recent tremors have shaken nearby towns.

                  The last evacuation was in December 1994, shortly after the volcano became
                  active again after lying dormant since 1927. It has been 800 years since its last
                  catastrophic eruption.

                  Copyright 2000 The Associated Press.