At least three people dead, one missing in Madrid explosion

At least three people have died after an explosion rocked the center of the Spanish capital, Madrid, and caused a building to partially collapse.

At least 10 others were injured in the incident and one person is still missing.

City officials have released a statement clarifying that the blast had been caused by a gas leak.

Reports suggest that four floors of the building have been completely destroyed.

It occurred when gas workers were repairing a boiler at the back of the building in the central Puerta de Toledo area of the capital.

Those killed in the incident included an 85-year-old woman passer-by and two men. 

Spanish media reported that the missing person is one of the men who had been working on the boiler.