At least three people died and eight more were injured when an explosion in central Madrid blew apart a building on Wednesday.

One of the people injured was in serious condition and transferred to hospital. The building belonged to the Catholic Church and an official said a volunteer was still missing.

Initial investigations suggested that the blast in Calle Toledo, a street leading out from the city centre, had been caused by a gas leak, mayor Jose Luis Martinez-Almeida said.

Smoke billowed out of the partly collapsed building and rescue workers evacuated elderly people from a nearby nursing home.

The top five floors were totally destroyed, with walls blown out, while the bottom two floors were still mostly intact, but charred in places from the flames.

The building was a complex that provided residential training for priests and also gave meals to homeless people, a neighbour said.

La Salle La Paloma School confirmed to HuffPost Spain that all the students at the school next door to the blast site were safe and that none of them had been outside when the explosion occurred, minutes before 3pm.

“We were at home, the windows were moved and we heard a huge explosion, we live 200 meters from the building that has collapsed, and everyone has started to go out onto the terraces and balconies,” said a parent whose daughter attends the school.

“My wife started to cry as soon as she heard the news and I ran away. I still have the anguish inside.

“At school they told us that the children had not gone in the playground today, which is covered with rubble, because of the snow and the rain. That has saved them.”