Mexico City – The Popocatépetl volcano is at it again.
Rumblings from the volcano, southeast of Mexico City, has caused Mexican authorities to raise the alert level due to increased activity.
It's now at the fifth step on a seven-level warning scale.
The National Disaster Prevention Center says a lava dome is growing in the volcano's crater. 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 center said in a statement late Monday 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 alert is now at the highest level of the yellow stage; the next stage is a red alert, in which evacuations would presumably begin.
Last August, the volcano spewed out ash from its crater.
Mexico's national disaster prevention agency said the volcano shot out ash for more than a half mile (a kilometer) into the sky four times and there was a possibility that the ash could have fallen onto Mexico City.
The last time the volcano erupted was in 2000.
The name Popocatépetl comes from the Nahuatl words for "it smokes" and "mountain."
Based on reporting by The Associated Press.