KHAN YOUNIS — At least 17 people were killed and dozens of others were injured early Friday morning after artillery fire struck a school and a residential home in Gaza’s southern city of Khan Younis.

Two artillery strikes hit Haifa School – where displaced residents were sheltering – and killed 12 people — “the majority of those children,” Nahedd Abu Etaimah, one of the directors of the Al-Nasser Hospital, who spoke with some of the injured, told CNN Friday.

Earlier, five people, including children, were killed after a house in western Khan Younis was hit, Abu Etaimah said.

Videos circulating on social media showed doctors treating two injured children at a hospital. In one particular video, a young boy who appears to be unconscious is brought in on the back of a mini truck. He is carried into the hospital by a paramedic and laid down on the floor as doctors treat him.

CNN has reached out to the IDF for comment.

Khan Younis is in southern Gaza. Civilians from northern Gaza fled to this area in thousands when Israel asked them to evacuate to escape strikes. Now, as Israel has expanded its ground operations to the south, it repeatedly asks civilians in several blocks — numerical units in a map designed by the IDF to designate areas inside Gaza — to evacuate. In the past week, it once asked civilians in some areas to go to a coastal area with few facilities, and another time it asked them to move to displacement shelters. — CNN