The huge stratovolcano in central Mexico has spewed ash and smoke and experts have recorded several low-level emissions over the last few days.
The volcano, which is located just 34 miles from the country’s capital Mexico City, has a history of major eruptions – and a further blast could put thousands of nearby residents at risk.
The huge volcano last erupted in September this year.
Last month’s eruption was followed by 24 hours of explosions and earthquakes in the area.
According to the National Centre for Disaster Prevention (Cenapred), the volcano has had 34 exhalations and 5 explosions in the last 24 hours.
And 24 hours later, at 3.07am local time, the stratovolcano had had 215 minutes of exhalations and seismic movements.
In July this year Popocatepetl spewed ash and lava more than 6,500ft into the air in the middle of the night prompting authorities to impose a seven-and-a-half mile exclusion zone.
Residents of nearby towns Morelos and Edomex were warned to stay away after the volcano blasted a huge plume of smoke more than two miles into the air.
Authorities took the precautionary measure when witnesses reported an “explosion” at the active volcano.
In 2013, lava was seen pouring down the mountainside twice, in May and July, leading to fears the event could be repeating itself.
The volcano is the second highest peak in Mexico and standing at 5,426m, it can be seen from the capital city.
Volcanic activity has become more and more frequent with more than 12 eruptions in the last six years.
Five climbers who were on the volcano were killed when it erupted in April 1996 but there have been no deaths since.
Mexican authorities fear a violent eruption could threaten the capital which is home to nearly nine million people.
In January 2001 there was an eruption so big it could be seen by astronauts on the International Space Station.
Despite being an active volcano, Popocatepetl, which means the Smoking Mountain in the native Nahuatl language, was successfully climbed by Spanish explorers for the first time in 1519.