Given the task definition and input, reply with output. In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.

Mexico City (CNN) -- Scientists recorded continuing volcanic activity Tuesday in Mexico's Popocatepetl volcano, which sits just southeast of Mexico City and its more than 19 million residents. 
  
 Local government officials and residents began taking precautions, with schools in the zone near the volcano closing Tuesday and the government advising residents to close windows and avoid the outdoors. 
  
 Activity had decreased in Popocatepetl overnight, but eight exhalations of low intensity were recorded, Mexico's National Center for the Prevention of Disasters said. 
  
 A low-amplitude tremor lasting 40 minutes early Tuesday morning was also felt, the agency said. 
  
 Officials placed the alert at Popocatepetl -- which means "Smoking Mountain" in the native Nahuatl language -- at Yellow Level 3. This means there is a probability of explosive activity of an intermediate to high scale, an eruption of lava and a spewing of ash. 
  
 A glow was visible inside the crater overnight, the agency said. 
  
 Popocatepetl is one of Mexico's highest peaks and last had a major eruption in 2000. It is located in a national park southeast of Mexico City and can be seen from there on a clear day. 
  
 Already, scientists have observed a continuous column of water vapor and moderate amounts of ash rising from the crater. Falling ash was reported in the city of Puebla, the capital of the state. 
  
 A 7-mile perimeter around the volcano has been cleared, and the Puebla state government asked residents to limit travel between cities near the volcano. 
  
 To guard against falling ash, residents should close doors and windows, cover water tanks and food and avoid outdoor activities, the government said. ||||| Authorities in Mexico have raised the alert level for the Popocatepetl volcano southeast of Mexico City due to increasing activity. It's now at the fifth step on a seven-level warning scale. 
  
 A plume of steam rises from the Popocatepetl volcano seen from the city of Puebla, Mexico, Saturday April 14, 2012. An early morning exhalation from the volcano sent ashes to towns near the area as moderate... (Associated Press) 
  
 A lava dome is growing in the volcano's crater, the National Disaster Prevention Center said Tuesday. The 17,886-foot (5,450-meter) volcano also has been spewing fragments of incandescent rock recently, as well as water vapor and ash. 
  
 The volcano could experience "significant explosions of growing intensity that hurl incandescent rocks significant distances," large ash showers and possible flows of mud and molten rocks down the volcano's flanks, the center said. 
  
 The agency said the area has been closed to visitors and urged people to stay at least seven miles (12 kilometers) from the crater, which is about 40 miles (65 kilometers) southeast of Mexico's capital. It also recommended that people in the surrounding areas clean ash from weak rooftops and to cover their mouths to avoid inhaling it. 
  
 The alert is now at the highest level of the yellow stage; the next stage is a red alert, which presumably would prompt evacuations to begin. 
  
 Known as "El Popo," the volcano staged its most violent eruption in 1,200 years on Dec. 18, 2000, when an explosion sent up a plume of red-hot rock and forced the evacuation of thousands of people who live at the volcano's base. 
  
 The volcano, which seats in the central states of Mexico, Puebla, and Morelos, has been erupting intermittently since December 1994. |||||

Officials are so uneasy about the rumblings of the now-glowing Popocatepetl volcano near Mexico City that they've shut down nearby schools, and warned travelers to stay away. Eight low-intensity "exhalations" and a 40-minute tremor from the shuddering volcano have been measured by Mexico's National Center for the Prevention of Disasters, reports CNN. The volcano threat has been raised to level 5 out of a possible 7, meaning there's a high probability of some kind of major activity, according to AP. A lava dome is building in the volcano, and Popocatepetl could experience "significant explosions of growing intensity that hurl incandescent rocks significant distances," large ash showers, and lava flows down the volcano's flanks, the center warned. 'El Popo,' which can be seen by Mexico City's 19 million residents on a clear day, is the highest peak in the nation, and last had a major eruption in 2000.