Mexico has been put on alert after a volcano started spewing hot ash and rock close to its capital city.

The country's National Centre for Disaster Prevention has warned people to stay away from Popocatepetl near Mexico City after 200 minor eruptions were recorded in 24 hours.

It has issued a level three yellow alert, indicating possible magma expulsion and explosions of increasing intensity.

Image: The Popocatepetl volcano has been spewing hot rock, ash and gas

The alert - the third highest - is one level below a red alert that would trigger preparations for an evacuation.

The 17,900ft (5,450m) stratovolcano has been particularly active in recent months and has now been spewing hot rock, ash and gas.


Image: Soldiers check an evacuation route near the volcano

It has sent pieces of burning rock showering about one and a half miles (2.4km) down its slopes, which has caused fires in surrounding grassland.

Several towns reported ash falling on them from the explosion.

Image: Ash and smoke could be seen from Puebla, central Mexico

Some 25 million people live within about 60 miles (97km) of the volcano's crater.

A major eruption at Popocatepetl in 2000 forced an evacuation and saw nearly 50,000 residents in three states surrounding the peak flee the region.