Reports say Guatemala’s most violent volcano eruption in more than a century has killed at least 25 people.

The Fuego volcano, about 40km south-west of the capital Guatemala City, spewed rocks and ash into the sky on Sunday.

Lava flows hit villages, killing people inside their homes. Hundreds were injured and many are missing. The country’s main airport is closed.

President Jimmy Morales has declared three days of national mourning.

In a statement issued late on Sunday, he spoke of the nation’s “deep pain” caused by the “irreparable losses” in human lives.

Fuego is one of Latin America’s most active volcanoes. A major eruption devastated nearby farms in 1974, but no deaths were recorded.

Another eruption in February this year sent ash 1.7km into the sky.

Sunday’s event was on a much greater scale. Molten rock rushed down the mountainside and engulfed villages. Ash reached up to more than 6km.

This is Guatemala’s deadliest such event since 1902, when an eruption of the Santa Maria volcano killed thousands of people.

Hundreds of personnel from the police, Red Cross and military have been deployed, organising evacuations and setting up temporary shelters.

Other towns affected include Alotenango and San Miguel los Lotes.

Rescuers are still trying to reach a number of villages and the death toll is expected to rise.

Several children are among the dead.

Volcanic ash has fallen as far as Guatemala City. Soldiers have been clearing the runway at the city’s La Aurora airport.

A total of about 1.7 million people have been affected in four regions.

Officials have advised people to wear masks as protection against falling ash.