(NewsNation) — As the war in Israel continues for the sixth day, hundreds of U.S. citizens are stuck in Gaza as Israel launches heavy air strikes on the territory.

According to reporting from NPR, between 400 and 600 American citizens are trapped in the small area of land at the center of the conflict. Those citizens, along with Gaza’s more than two million residents, are left to find shelter amid heavy bombardment from Israeli missiles and a total siege that prevents fuel, water or food from entering the area.

Those trapped in the Gaza Strip include Palestinian Americans visiting family and humanitarian workers.

While the U.S. is working to arrange charter flights to evacuate U.S. citizens, the State Department’s travel advisory for Gaza notes that routine or emergency services are not available to Americans in Gaza as U.S. government employees are prohibited from traveling there.

The U.S. Embassy in Jerusalem advised U.S. citizens to check the Rafah crossing into Egypt, which has been temporarily closed due to damage from Israeli missile strikes.

Israel has issued warnings before bombardments, urging civilians to evacuate before launching strikes. The struggle is that in such a small area, people are running out of places to go.

Roughly the same size as Philadelphia with a population density similar to London, the Gaza Strip is bordered by Israel on two sides and Egypt by one, with access to the sea on the remaining border limited by Israel.

Even prior to the unprecedented Hamas attack that resulted in the declaration of war from Israel, access to the region was strictly controlled. For 16 years, Israel has maintained a blockade on Gaza, with the construction of an “Iron Wall” and limited crossings only available to Palestinians who had permission from Israeli authorities.

Egypt has also closed its border to those looking to cross from Gaza.

The restrictions have led to widespread poverty and shortages of essential items like food and medical supplies. Civilians living in Gaza, unlike those in Israel, have no access to air raid sirens or bomb shelters. Human Rights Watch has referred to the area as resembling an “open-air prison.”

Hamas took total control of the Gaza Strip in 2007 from the Palestinian Authority, which continues to govern in the West Bank. Tensions with Israel have continued to rise over the years, with 6,407 Palestinians killed from 2008 to just prior to the current war and 308 Israeli deaths, according to United Nations data. Among the Palestinian deaths, 5,360 were in Gaza.

Humanitarian aid groups have been calling for corridors to be open to allow aid and critical supplies to civilians. The United Nations has also called on all parties in the conflict to follow international humanitarian law.

The Biden administration has been in negotiations with Israel and Egypt regarding a humanitarian corridor, which could also help U.S. citizens attempting to leave Gaza. However, there has been no progress made on the issue so far.