BEIJING, Nov. 20 (Xinhua) -- Beijing police have detained 18 people in relation to the fire in an apartment that killed 19 people on Saturday.

A fire broke out Saturday night at a three-story apartment at Xinjian Village of Daxing District at the southern suburb of the city. A total of 19 people died. Among the victims, eight were under 18 years old, He Rui, deputy chief of Daxing District, said at a press briefing late on Monday.

Eight people were taken to hospital. Seven of them are out of danger and one remains in a critical condition, he said.

Preliminary investigation showed there was a 5,000-square-meter refrigeration facility under construction at the basement of the apartment. Fire-fighters suspect the fire might have started there.

The 18 detainees include seven who managed the apartment block, seven electricity workers, and four construction workers at the refrigeration facility. None of the 11 workers holds qualifications as required by the authority, police said.

More than 400 people lived in the apartment block and all have been relocated, He said.

The district government has set up medical, legal and family teams to deal with affairs arising from the deadly fire. They contacted 95 family members of the victims.

Police are investigating other suspects.

Beijing has ordered a 40-day city-wide safety check. Local officials are urged to check every village and every courtyard for safety risks.