Doctors have warned that 130 premature babies' lives are in imminent danger in Gaza unless fuel arrives at hospitals soon.
Israel implemented a full siege as part of its war on the Palestinian enclave following a surprise 7 October attack launched by Hamas militants inside Israeli territory.
For the first time since the total siege was imposed, 20 trucks carrying aid entered Gaza through the Rafah crossing with Egypt on Saturday. But they did not bring vitally needed fuel, a supply Israeli authorities have blocked from reaching the strip.
"The world cannot simply look on as these babies are killed by the siege on Gaza," Melanie Ward, chief executive of UK-based charity Medical Aid for Palestinians (MAP), said on Saturday in an emailed press release.
"We call on world leaders to demand that Israel urgently allows fuel into Gaza's hospitals. A failure to act is to sentence these babies to death."
Scottish First Minister Humza Yousaf responded to a social media post made by MAP about the doctors' warning that included two photos of babies in incubators.
"How can this be justified? What crime have these babies committed?" Yousaf asked.
"This is why collective punishment must be called out and condemned.
"Let aid in, including fuel. Otherwise, these images should haunt us for the rest of our lives.
"A ceasefire is needed and needed now."
There are six neonatal units at Gaza hospitals, including at Al-Shifa and Nasser.
Doctors at all six hospitals looking after premature babies have urgently called for fuel to save the children's lives.
Hamas's surprise attack killed around 1,400 people in Israel. Israel has since repeatedly bombed Gaza, killing almost 4,400 people.
Gaza has been under an Israeli-led blockade since 2007. The full siege imposed this month is a tightening of these measures.