UNITED NATIONS, April 4 (Xinhua) -- "Forgive me, Mom. I just wanted to help people. I just wanted to save lives," breathed a dying volunteer in the Gaza aid convoy ambush, a humanitarian official said on Friday.

Recordings of the deadly March 23 Israeli ambush of the emergency vehicle convoy also contain Israeli soldiers' conversation in Hebrew with a missing worker, said Palestinian Red Crescent Society (PRCS) President Younis Al-Khatib.

PRCS Vice President Marwan Jilani joined the society head at a briefing in the UN headquarters. They said ambulance workers speak Hebrew in addition to Arabic.

Al-Khatib said the "heartbreaking" dying words of the ambulance worker were discovered on the phone taken off his body. The deceased worker was not identified.

Published reports identified the still-missing worker as Assad al-Nassara.

"We have the recordings," said Jilani, referring to Assad. "We could hear him say they are firing at us. We heard a conversation in Hebrew between soldiers and Assad."

"Has Assad been killed or is still missing? Why keep us in the dark?" asked Jilani.

During a Security Council meeting on the attack on Thursday, Riyad Mansour, the permanent observer for the State of Palestine to the United Nations, handed up a short video recording of the attack and described a second recording.

"They were shot in heads and chest, many of their hands tied," the envoy said. "They were executed for performing their sacred mission, killed for trying to save lives."

Jilani, who said it was standard operating procedure to video record ambulance operations, said one of the recordings showed the ambulances and a fire truck using flashing emergency lights and sounding sirens.

Israel has said the convoy was not using lights or sirens.

Recordings also were made of radio transmissions between dispatchers and the ambulances.

Bodies of the 15 workers and their mangled vehicles were discovered last week, after a search, in a shallow sand grave. Aid workers varied in age from young volunteers to married men with children.