Watch: Mexican Volcano Eruption Caught on Video

The largest volcano in Mexico, Popocatépetl, showed some rare activity over the weekend, including at least one explosion. The overnight blast was caught on camera by geologists. Check it out below.

Leading up to the explosion, the volcano was showing signs of activity. There were tremors, earthquakes, and exhalations containing volcanic gas and water vapor. Right now, Popocatépetl has a gas emission escaping from the south, mostly made up of steam.

Shortly after the blast, geologists and federal police flew up to volcano's peak to assess the damage. They found that the crater had expanded to a diameter of 370 meters, and the depth had reached 110 meters. They warn that this cavity will likely fill with lava overtime, until it cools to form the new mountaintop.

The explosion may be a bad sign for nearby towns and cities, and some are already in mild danger. CENAPRED, Mexico's Nation Center For the Prevention of Disasters, has set the "Volcanic Traffic Light" for Popocatépetl at "yellow." The traffic light is a danger assessment system, not unlike the Richter scale for earthquakes or 1-5 category ratings for hurricanes.

According to CENAPRED's website, the yellow light means that people residing near Popocatépetl must follow some strict safety guidelines for the foreseeable future. Geologists are predicting heavy ash fall in surrounding areas, mudslides and pyroclastic flows, and possibily even more explosive activity.

CENAPRED is urging people to keep at least twelve kilometers away from the volcano. They warn that Civil Protection Authorities will be in the area, and people need to listen to them to maintain their safety. They also recommend people stay inside as much as possible, and wear masks to cover their mouths and noses while outside. CENAPRED also says that contact lenses can cause serious irritation with volcanic ash in the air.