Mexico has raised the alert level around the huge Popocatepetl volcano, after it began spewing ash and steam.

墨西哥波波卡特佩特火山开始喷出灰尘与蒸汽，政府提高了周边地区的警戒程度。

Tens of thousands of people live in the shadow of the volcano
Several schools around the 5,450m (17,900 foot) volcano were closed as a precaution, and evacuation shelters have been prepared.

The National Disaster Prevention Centre (Cenapred) raised the alert to "yellow stage three" - the third-highest level.

The volcano lies around 70km (40 miles) from Mexico City, and is visible from the capital on a clear day.

"We can hear the roar of the volcano, sometimes we can feel its force," Concepcion Perez from the town of Xalitzintla in Puebla State, 12km (seven miles) from the volcano told the French news agency Agence France-Presse.

Cenapred officials said the alert could remain for weeks or months until the volcano's activity diminished.

Popocatepetl - which means "Smoking Mountain" in the indigenous¹（本土的） Nahuatl language - is Mexico's second-highest peak.

In 2000 a major eruption² forced the evacuation of tens of thousands of people from nearby communities.