Authorities have blamed a car driving against traffic and colliding with oncoming vehicles as the reason for the explosion. Rescue workers are searching for bodies in the Nile River, fearing some may have fallen in.An explosion outside Egypt's National Cancer Institute (NCI) killed at least 19 people and injured 30 others, Egypt's interior ministry said Monday.Authorities said the explosion was caused by a car driving against traffic, colliding with three other cars.What we know so far:

• The car drove against traffic on Cairo's corniche in the southern district of al-Manyal
• The multiple car collision caused a fire that affected parts of the nearby hospital
• People injured by the collision were transferred to other hospitals
• The country's top prosecutor ordered an investigation into the incident

Patients in hospital are 'well'State-run Cairo University, which hosts the NCI, denied claims that the explosion had taken place inside the institute or that the fire had spread to the center, as initially speculated."All the patients and workers at the center are well," the university said.Health Minister Hala Zaid discussed the death toll with Egyptian television channel CBC Extra but did not comment on the causes of the explosion, only that the incident took place in front of the hospital and not inside, as initially speculated.The health minister said that ambulances were sent to the hospital to transfer patients to other hospitals. Zaid added that the search continues for other bodies that could have fallen into the Nile River in front of the hospital.Where is the NCI? The institute is in an area of Cairo that also includes several government offices, including the Justice Ministry building.