A building has collapsed in central Madrid and up to four people have been reported missing. Emergency services rushed to a rescue effort after several floors collapsed inside a hotel that was under construction on Hileras Street, leaving several injured.

Initially, three men and one woman were reported missing according to Madrid city officials, but sources from the National Police have confirmed two, reports Spanish news organisation, El Pais. One construction worker was taken to hospital for a leg fracture, while others were treated for injuries and shock, according to Madrid Emergency Services.

Crews worked to stabilise the building so they could start clearing the debris and allow the Municipal Police Canine Unit to enter and search for the missing, a spokesperson for Madrid Emergency Services confirmed.

A construction worker who asked to remain anonymous told El Pais: “There could have been up to 40 people inside the building. At the moment of the collapse, we heard a noise from the floors, and then just a cloud of dust.”

The Spanish government delegate in Madrid, Francisco Martín, told local press that the exact number of workers present at the building near the popular Puerta del Sol square was still being determined.

He also stated that it was a workplace accident, and authorities were analysing the possible impact on neighbouring buildings. He added that the "entire perimeter" was evacuated.

According to the building register, it was a six-floor building constructed in 1965, with a basement parking garage. The plot measures 1,070 square meters.