An explosion destroyed part of a residential building in Madrid on Wednesday - killing at least four people.

News reports said that the explosion occurred while repairs were being conducted on a gas boiler.

The explosion, which happened near Toledo Street in central Madrid, ripped through the building owned by the area's Catholic parish. The parish said that one of the people killed in the explosion was an electrician - a father of four - who was working on the boiler.

The building belonged to the La Paloma Catholic Parish.  Madrid Archbishop Carlos Osoro said that some of their priests were living in some of the apartments in the building. He confirmed that none of their clerics were among the victims.

"Everything shook, it felt like the roof was falling on us. We were terrified when we saw the amount of smoke coming out of the church's building," one of the building's residents told reporters.

Madrid emergency service said that at least 11 people were injured.

Madrid Mayor José Luis Martínez-Almeida said no one at the school was injured.

Madrid police said firefighters put out small fires throughout the building before they brought in search dogs and rescue teams. Engineers are assessing the condition of the structure.

A reporter from The Associated Press said that he saw emergency workers carry bodies away from the area.