MEXICO CITY — Seismic activity has increased at the Popocatepetl volcano near Mexico City, leading authorities to alert towns in two central states and the capital.
Mexico's National Disaster Prevention Center says the white-capped volcano spewed a plume of steam more than a half mile (1 kilometer) into the sky. The volcano shook during Saturday night, sometimes emitting glowing rock over the crater.
The government deployed soldiers and federal police to the area Sunday in the event of a bigger eruption, and officials closed off a seven-square-mile (18-square-kilometer) zone around the cone of the 17,886-foot (5,450-meter) volcano. State authorities prepared shelters.
Popocatepetl has put out small eruptions of ash almost daily since a round of activity began in 1994. The eruptions started strengthening two weeks ago and have increased even more this weekend.
Related on HuffPost:
Marum Volcano - Ambrym Island
<a href="http://www.volcanodiscovery.com/vanuatu/" target="_hplink">Volcanodiscovery</a> considers the Marum Volcano in the southern Pacific Island of Ambrym one of the most unspoilt and intact places of the earth. In 2010, a Youtube video of volcanologist Geoff Mackley climbing into the boiling Marum crater went viral. "A lot of people might think I'm crazy," <a href="http://www.huffingtonpost.com/2010/10/05/geoff-mackley-daredevil-r_n_750650.html" target="_hplink">said</a> the freelance photographer from Auckland, New Zealand. "The incredible noise... the heat.... the toxic gas... the falling rocks...the danger, nothing else in life will ever compare to the mind blowing rush of being so close to a spectacle like this!"
Eyjafjallajökull Volcano - Iceland
Located under a glacier, Iceland's Eyjafjallajökull volcano <a href="http://www.huffingtonpost.com/2010/04/14/iceland-volcano-evacuatio_n_536811.html" target="_hplink">erupted</a> on April 14, 2010, producing scenic lava flows and a plume of gas-rich volcanic ash which disrupted air travel and caused regional mayhem for several weeks. Eyjafjallajökull, some 75 miles (120 kilometers) east of Reykjavik, <a href="http://www.huffingtonpost.com/2010/04/14/iceland-volcano-evacuatio_n_536811.html" target="_hplink">erupted</a> March 20 after almost 200 years of dormancy.
Llaima Volcano - Chile
The Llaima volcano in southern Chile <a href="http://www.huffingtonpost.com/huff-wires/20080101/chile-volcano/" target="_hplink">spewed</a> lava and a thick column of ash, which rose more than 9,300 feet into the sky in January 2008. The eruption forced the emergency evacuation of some 150 people from the Conguillio National Park where the volcano is located, 400 miles south of Santiago.
Erta Ale Volcano - Ethiopia
Ethiopia's Erta Ale is considered to be one of the most active volcanos containing basaltic lava, which can <a href="http://www.huffingtonpost.com/2012/06/25/volcano-garbage-ethiopia-erta-ale_n_1625517.html?utm_hp_ref=travel&ir=Travel" target="_hplink">rise</a> to a temperature of 1,200 degrees Celsius, according to the <a href="http://www.thesun.co.uk/sol/homepage/news/4394130/Rubbish-dropped-in-volcano-to-find-what-would-happen-to-a-human.html" target="_hplink">Sun</a>. Active since 1906, Erta Ale, which translates to "smoking mountain" in the local language, is one of five lava lakes in the world, according to <a href="http://physicsbuzz.physicscentral.com/2010/12/erta-ale-gateway-to-hell.html" target="_hplink">Physics Central</a>.
Mount Etna - Italy
In 2012, Europe's tallest active volcano Mount Etna in southern Italy <a href="http://www.huffingtonpost.com/2012/01/05/mount-etna-erupts_n_1186391.html" target="_hplink">came back to life</a> and released a dense cloud of ash lava.
Mount Sakurajimas - Japan
Mt. Sakurajima, one of Japan's most active volcanoes, <a href="http://www.huffingtonpost.com/2012/03/13/sakurajima-volcano_n_1341845.html" target="_hplink">erupted </a> several times in March 2012.
Kilauea Volcano - Hawaii
A new vent opening at the <a href="http://www.huffingtonpost.com/2011/03/07/kilauea-hawaii-volcano-eruption_n_832292.html" target="_hplink">Kilauea </a>volcano, one of the world's most active, sent lava shooting up to 65 feet high in May 2011. <a href="http://www.huffingtonpost.com/2011/03/07/kilauea-hawaii-volcano-eruption_n_832292.html" target="_hplink">Kilauea</a> has been in constant eruption since Jan. 3, 1983.