Pakistani police say they have registered a murder case against the owners and managers of a garment factory in the southern city of Karachi where a fire killed 258 people.
Under the law, registering a case is a required step before charges can be made against suspects, following a complete police investigation.
Senior officer Amir Farooqi said today the police are investigating the owners and managers because of reports that many of the factory's exit doors were locked at the time of the fire.
Many escape routes were blocked with large bundles of cloth and basic safety regulations were not followed.
Mr Farooqi says police are also investigating government officials who failed to enforce fire safety regulations.
The fire broke out on Tuesday night and burned well into the next day.
Also on Tuesday night, a fire swept through a four-storey shoe factory in the eastern city of Lahore, killing 25 people. Some died from burns and others from suffocation.
The factory was illegally set up in a residential part of the city. The fire broke out when people in the building were trying to start their generator after the electricity went out. Sparks from the generator made contact with chemicals used to make the shoes, igniting the blaze.