A 72-year-old man was arrested in connection with the fire at the Marien hospital in in the northern German city of Hamburg., police said.

The man, a patient at the hospital, could potentially be considered a suspect, according to the police. The fire which caused the deaths of three people, with at least 34 others injured.

The suspect is reportedly set to be brought in front of a judge on Monday.

"In the course of collecting witness examination, there were signs that a 72-year-old patient could be a strong suspect of the fire," police said, adding that the patient's mental state is being examined as part of the ongoing investigation. 

Authorities previously said 16 suffered serious injuries, and at least one person was in a life-threatening condition.

What do we know about the fire?

The fire started shortly after midnight in one of the buildings of the Marien Hospital in the city's Hohenfelde neighborhood.

Heavy smoke then engulfed all floors of the building, a fire department spokesperson said.

It was not immediately clear how the fire started. It apparently broke out in a room in the department for geriatric care on the building's ground floor. 

A large contingent of emergency service personnel was deployed to control the fire and bring those in the hospital to safety.

Patients evacuated

In the early hours of Sunday, authorities reported that the fire had been extinguished. 

Patients who were in the affected building have been evacuated, officials said.

Some of the injured patients were being treated in the hospital's emergency department, while others were taken to nearby hospitals.

Edited by: Sean Sinico and Wesley Dockery