Fire authorities in Beijing said Thursday that they have ordered a citywide overhaul of fire control measures after a building blaze earlier this week left 18 people dead and two dozen others injured.

The overhaul is aimed at preventing major fires and is expected to last through May, said a spokesman with the city's fire department on Thursday.

The overhaul will focus on rural-urban areas, specifically rented houses, small hotels, bars and Internet cafes, where fire safety enforcement is often lax, he said.

Authorities will also run safety checks on high-rise buildings, construction sites and densely-populated areas.

The fire department has vowed to shut down businesses that are in serious violation of fire safety regulations.

The safety overhaul came after a fire swept through an illegally constructed building in suburban Beijing on Monday, killing 18 people and injuring 24 others.

Eight of the injured were still in critical condition as of Thursday night, according to the city's health bureau.

Most of the dead were identified as migrant workers hired by a garment workshop that operated out of the building's ground floor.

Police said the fire was caused by a short circuit in an electric bicycle stored in the workshop. Poor safety conditions in the building and its surrounding neighborhood prevented victims from escaping and hindered rescue efforts.