The Popocatepetl volcano in Mexico has spewed ash almost four kilometres into the air following an eruption from its crater.
Video footage shows steam, gas, ash and fragments shooting into the air in what official sources say is the biggest eruption in recent weeks.
Jesus Morales, director of Civil Protection of the State of Puebla, told AFP that the incandescent matter reached areas as far as two kilometres from the crater and caused fires north of the volcano.
"There were clouds at the time of the phenomenon, so it was possible to observe the shock wave accompanied by the fumarole and hot material," he said.
The National Disaster Prevention Centre (Cenapred) said that over 24 hours the volcano registered 78 exhalations and tremor episodes.
According to the Latin Times, residents living as far as 24km away heard the explosion, saying it sounded like a rocket and shook windows.
Cenapred said there is a "constant emanation of gas to the south west side of the volcano" and officials have restricted access over a 12km radius around its crater.
Roads between Puebla and Mexico State are only open to controlled traffic.
The volcano alert level is currently on Yellow Phase 2 - it was dropped from Yellow Phase 3 on 7 June following weeks of activity.
Around 4.5m people live within a 50km radius of the volcano, with around 650,000 in areas considered high risk.
In May, shelters were prepared for people living in the surrounding areas, and hundreds of police were placed at the site ready for an evacuation.
The 5,452m volcano is one of the most active in Mexico and several eruptions have been recorded since 1994. It has emitted ash almost every day since then.
After the alert was raised in May, experts warned that this may be the end of the volcano. Cenapred said: "After the explosive event, it could be seen that the dome had slightly deflated, although it did not diminish considerably in volume. This event might represent the beginning of the dome´s destruction."