At least two people are believed to have died after an explosion on Wednesday devastated a building belonging to a Catholic parish in the Spanish capital, Madrid.

The explosion took place near the Puerta de Toledo in central Madrid after 3 p.m. local time on Jan. 20.

The archdiocese of Madrid said that the explosion may have been caused by a gas leak in the building owned by the Parish of the Virgen de la Paloma and San Pedro el Real.

It said that priests lived on two floors of the building, which also contained space used by the parish and Caritas.

“Two of the priests are OK and one has been transferred to the hospital. An attempt is being made to locate a layman who was with them at the time of the explosion,” the archdiocese said.

The archdiocese added that Cardinal Carlos Osoro Sierra, the archbishop of Madrid, had traveled to the scene of the explosion to offer support to members of the parish.

“I pray for the Christian community in these difficult times and I pray for the victims,” he wrote on his Twitter account.

ACI Prensa, CNA’s Spanish-language news partner, reported that Madrid’s mayor, José Luis Martínez-Almeida, had confirmed that at least two people had died as a result of the explosion.

The mayor added that the building was still burning, but firefighters had not yet extinguished the flames due to the risk of further explosions.

ACI Prensa said that local residents, including members of a nursing home, had sought refuge in neighborhood cafes.

The explosion damaged nearby buildings, shattering glass and showering the street with debris.