A fire broke out at an apartment building in northern Seoul, leaving two people dead and injuring 29 others, firefighters said Monday.

The blaze occurred at the third floor of the 23-story apartment building in Seoul's Dobong district at around 4:57 a.m., according to fire services.

Two men in their 30s and a woman in her 70s were found in a state of cardiac arrest and sent to a hospital. The two men were pronounced dead, but the woman is known to have regained consciousness.

The other 28 people suffered injuries, including smoke inhalation, and 20 of them received treatment at hospital.

A man and woman in their 70s, who resided on the third floor of the apartment where the fire broke out, are believed to have jumped outside to save their lives.

A couple in their 30s who lived on the fourth floor jumped from their home while carrying their two children. But the 33-year-old husband, identified only by his family name Park, died after being rushed to hospital. His wife had her shoulder injured, and the children suffered hypothermia and smoke inhalation, but are known to be in stable condition.

A 38-year-old man who resided on the 10th floor, was found in cardiac arrest on a stairway. Authorities presumed he might have inhaled too much smoke during the evacuation.

About 222 firefighters battled the fire and extinguished it about three hours after the fire started. An estimated 200 residents were ordered to evacuate in the wee hours.

The fire charred the exterior of the apartment building, covering about 17 stories.

Police and firefighters are investigating to determine the exact cause of the accident.

"There seems to be no foul play related to the fire," a police officer said, adding that a joint inspection into the scene will be carried out Tuesday.

Seoul Mayor Oh Se-hoon said Monday the city government and the Dobong district will make a joint effort to help the citizens affected by the fire return home as soon as possible. (Yonhap)