Health Minister Hala Zayed said at a press conference on Sunday night that among the injured, five remain in critical condition and that at least 54 people have been transferred from the cancer institute to other medical centres in the area, reports Efe news.
Zayed did not mention the cause of the explosion on Sunday evening, though she noted that it took place in front of the hospital and not inside, as was initially reported.
According to the state news agency MENA, the explosion occurred when a vehicle speeding wrong way down the street collided with other cars, causing a fire that affected part of the hospital.
Several vehicles were engulfed in flames outside the hospital and corroborated that there was a fire.
The Egyptian health official said that authorities were searching for other bodies that may have fallen into the Nile River, which is located beside the hospital.
The Office of Information of the University of Cairo, to which the cancer institute belongs, said in a statement that the explosion affected part of the building facade but that the staff and patients were safe.
Police sources initially speculated that the explosion might have originated from an oxygen container inside the building.
The Attorney General's Office has sent a team to the scene of the incident to begin the official investigation.
( With inputs from IANS )