Seventy-six injured Gazan residents have crossed from Gaza into Egypt on Wednesday, hours after the Rafah border crossing opened for the first time since the Israel-Hamas conflict began on Oct. 7, according to Palestinian Rafah Crossing spokesman Wael Abu Omar.

The World Health Organization said it's working with officials in Egypt to help establish "a comprehensive triage, stabilization, and medical evacuation system" and "ensure that psychological trauma support services are available to patients."

At least 335 foreign passport holders -- including dual nationals and foreigners -- also crossed from Gaza into Egypt on Wednesday, he said.

As the humanitarian crisis in Gaza worsens, 51 aid trucks crossed the border Wednesday to head into Gaza, he said. A total of 268 aid trucks have now entered Gaza.

President Joe Biden posted on social media on Wednesday confirming that the U.S. "secured safe passage for wounded Palestinians and for foreign nationals to exit Gaza."

"We expect American citizens to exit today, and we expect to see more depart over the coming days," Biden wrote.

Five American aid workers are among the foreign nationals who crossed the Rafah border from Gaza into Egypt on Wednesday, according to the Palestinian Children's Relief Fund.

A Rafah crossing spokesman said at least 335 foreign passport holders -- including dual nationals and foreigners -- have crossed from Gaza into Egypt.

Five American aid workers have crossed the Rafah border from Gaza into Egypt, according to the Palestinian Children's Relief Fund. They work for the Palestinian Children's Relief Fund, Catholic Relief Services and Doctors Without Borders.

The border crossing between Gaza and Egypt opened on Wednesday, allowing some foreign nationals and injured Gaza residents to exit the enclave for the first time since the Israel-Hamas conflict began on Oct. 7.

Seventeen ambulances, each transporting one injured Gazan, have crossed the border into Egypt, ABC News has confirmed.

The Rafah border crossing, which is controlled by Egypt, was expected to allow about 500 foreign passport holders to exit, according to the Gaza Borders and Crossings Authority, which released a list of names of those who would be allowed across.

At least 110 dual nationals have crossed the Rafah border into Egypt, ABC News confirmed.

Five American aid workers are among those at Rafah waiting to cross into Egypt, according to the Palestinian Children’s Relief Fund.

Gaza's Jabalia refugee camp, the most populous refugee camp in the region, was hit by a second airstrike on Wednesday, according to the Hamas-run Gaza Health Ministry.

The Israel Defense Forces confirmed that on Wednesday, "based on precise intelligence, IDF fighter jets struck a Hamas command and control complex" in Jabalia, and that Hamas fighters were killed in the strike.

"Hamas deliberately builds its terror infrastructure under, around and within civilian buildings, intentionally endangering Gazan civilians," the IDF said. "The IDF has been urging Gazans in this neighborhood to evacuate as part of its efforts to mitigate harm to civilians. The IDF continues to call on all residents of northern Gaza and Gaza City to evacuate southwards to a safer area."

The IDF also took responsibility for the first strike on Tuesday, saying the blast killed a Hamas official who the IDF claimed was one of the leaders of the Oct. 7 attack on Israel.

The United Nations Human Rights Office said, "Given the high number of civilian casualties & the scale of destruction following Israeli airstrikes on Jabalia refugee camp, we have serious concerns that these are disproportionate attacks that could amount to war crimes."