Col. Yamen Abu Suleiman, Director of Civil Defense in Khan Younis told CNN Monday that “today, 73 bodies were recovered” in the courtyard at the Nasser Medical Complex which brought the “total number to 283.”

Suleiman alleged that some of the bodies had been found with hands and feet tied, “and there were signs of field executions. We do not know if they were buried alive or executed. Most of the bodies are decomposed.”

CNN is unable to verify Suleiman’s claims and cannot confirm the causes of death among the bodies being unearthed.

CNN has reached out to the Israel Defense Forces (IDF) for comment following the discovery of the mass grave including whether bodies that had been buried at the hospital had been disinterred for DNA tests, and whether they had been reburied. CNN has sent several questions to the IDF on Sunday and Monday.

Previously, a Khan Younis Civil Defense spokesman and head of the search mission, Raed Saqr, told CNN that they are searching for the bodies of another 400 missing people after the Israeli military left on April 7.

A CNN stringer who visited the scene Sunday said people had buried the bodies of family members who had been killed in the grounds of the hospital in January as a temporary measure. When they returned after the Israeli withdrawal they found the bodies had been exhumed – apparently because the IDF was using DNA testing to determine whether any of the hostages held in Gaza were among the dead.

The bodies were then placed in at least one collective grave, the stringer said.

One man at the scene told CNN that he was yet to find the body of his 21-year old son, who was killed in January.

“I haven’t found him yet. We had buried him over there. But we can’t find him. And we wanted to make him a decent grave.”

Another man, who said his brother Alaa was also killed in January, said: “I am here today looking for him. I have been coming here to the hospital for the last two weeks and trying to find him. Hopefully, I will be able to find him.”

Pointing to a fallen palm tree, the man said his brother had been temporarily buried in that spot.

“I had buried him there on the side, but I can’t find him. The Israelis have dug up the dead bodies, and switched them. They took DNA tests and misplaced all the dead bodies.”

The man’s mother said they had been searching for two weeks and had been unable to find his body.

Another woman told CNN she had spent 10 days searching for the body of her daughter, who had been killed and buried in the hospital grounds late in January after a nearby residential building had been struck.

She said the Israelis “have dug out the dead bodies out and they switched them. She and her uncle’s wife were buried at the same hour.”

The mother added: “We have found the body of her uncle’s wife. But the rest we can’t find them.”

Saqr told CNN Sunday that Civil Defence personnel had been searching for bodies at the medical complex for three days so far and the operation was ongoing.

“We have information that there are 400 missing people, and we are continuing to search for the rest of the bodies.”

The IDF has said it has removed dozens of bodies from Gaza for DNA tests in Israel, before returning the remains in containers.

The area around the Nasser Medical Complex saw intense bombardment and combat in January and February. At the time, CNN reported on the burial of bodies in the hospital grounds because of a lack of safe access to cemeteries.