“There were piles of dead bodies, blood everywhere,” he added.
Twenty-two people were killed in shelling that lightly damaged the outside walls of the compound where the Red Cross has been operating.
It is located just south of a humanitarian zone identified by the Israeli army in the Palestinian territory.
“All of our buildings are very well known to all parties to the conflict,” Schomburg said.
Refusing to speculate on the source of the shelling, he said: “We’re not here to lay blame.
“But of course, this incident is one of several near misses that we have had … and we as the ICRC cannot operate like this.”
Many of the wounded were taken by ambulance to a nearby Red Cross field hospital for operations. Some did not survive.
No Red Cross employees were killed, Schomburg said, but two children of staff members required treatment for injuries sustained in the blasts.
It is not the first time Red Cross facilities have been damaged during the more than eight months of fighting between Israel and Hamas militants who control the Gaza Strip.
Schomburg said that recovering from the trauma of Friday’s strike would not be easy.
“Around the compound on the street, there were pools of blood, there were bodies strewn across the ground,” he said.
“We literally found body parts scattered in different areas, including within the compound.
“Frankly, it’s like nothing I’ve ever seen before. The scale of the suffering in such a short period of time was really very shocking for the team.”
04:23
GEN-Z VS GENOCIDE: HOPE FOR HUMANITY?
GEN-Z VS GENOCIDE: HOPE FOR HUMANITY?
The shelling came as Israel has stepped up its strikes in the Gaza Strip since war broke out after the October 7 attack by Hamas, which resulted in the deaths of 1,194 people, mostly civilians, according to an AFP tally based on Israeli official figures.
The militants also seized hostages, 116 of whom remain in Gaza although the army says 41 are dead.
Israel’s retaliatory offensive has killed at least 37,551 people, also mostly civilians, Gaza’s health ministry said on Saturday.
An Israel Defence Forces statement on Saturday said an initial inquiry found “there was no direct attack carried out by the IDF against a Red Cross facility”.
But the incident was still under review and “findings will be presented to our international partners”.
The Red Cross office is surrounded by a camp where several families of ICRC staff members live in tents. Schomburg said it was a “miracle” that none were severely injured.
Nonetheless “there was an overwhelming sense of fear amongst people that were clearly panicked and very desperate with nowhere to go”, he added.
Thousands of displaced Palestinians have been sheltering in tents in the coastal Al-Mawasi area since the outbreak of the fighting, prompting the recognition of the humanitarian zone by Israeli authorities.
“Our office here in Rafah, like all of our buildings and facilities, are all marked with the Red Cross emblem and are known by all parties,” Schomburg said.
“So how to explain the strikes we experienced yesterday? I think you will have to ask the parties involved in this conflict, and not us.”