Relatives of the victims have told the press they expect sabotage led to the blast and that once the three-day Muslim mourning period is up they will report to police to give testimony.
The blast was originally reported to have been caused by a gas leak, but locals living in the area and families of the victims said they suspect that someone tried to blow up a cellular antenna on the roof after years of attempts to destroy it.
The antenna was reportedly placed on the rooftop by the owner of the building, who had received threats from people nearby who blamed it for causing health problems for locals. In the past, residents said attempts had been made to torch it.
Shopkeepers in the Old City closed their doors early on Tuesday in mourning, and a number of locals said the blast was the worst tragedy they can remember in the city.