Palestinian schoolgirls, pictured through a hole in the roof of a classroom that witnesses said was damaged by Israeli shelling during a 50-day war last summer, attend a lesson on the first day of a new school year at Suhada Khouza school in Khan Younis in the southern Gaza Strip, Aug. 24, 2015. The highly populated strip could be uninhabitable by 2020, a U.N. report says. Reuters

After years of war and crippling economic blockades from Israel, the Gaza Strip could be uninhabitable for current residents as soon as 2020, according to an annual United Nations report released Tuesday. The 139-square-mile strip of land tucked between Israel, Egypt and the Mediterranean Sea is home to 1.8 million Palestinians, many of whom could be displaced if conditions remain severe.

"The social, health and security-related ramifications of the high population density and overcrowding are among the factors that may render Gaza unlivable by 2020," the annual U.N. Conference on Trade and Development wrote. "Gaza could become uninhabitable by 2020 if current economic trends persist."

The blockade was established by Israel in 2007 to disrupt the flow of goods and supplies into the Palestinian territory, which is a heavily disputed swath of land. While Egypt has allowed occasional movement across its border with the Gaza Strip, Israel has worked to stop transportation by air, land and water. Most of Gaza borders either Israel or the Mediterranean.

The blockade means that, aside from weapons, the Palestinians also have a difficult time receiving food aid from the United Nations. In 2008, a U.N. spokesman said the blockade had "become a blockade against the United Nations itself."

Palestinians bake bread on a clay oven in the city of Beit Lahiya in the northern Gaza Strip, Aug. 25, 2015. Reuters

Gaza has been hit by three Israeli military attacks in the past six years, which has exacerbated conditions for Palestinians. Residents couldn't repair their infrastructure, which already was debilitated from the blockade. That leaves an already poor population without needed resources and facing a lack of goods flowing into the territory.

"Short of ending the blockade, donor aid ... will not reverse the ongoing de-development and impoverishment of Gaza," the report read.

The most recent war, in 2014, killed an estimated 2,200 Palestinians and displaced half a million more. It also left 73 Israelis dead, and decimated homes, schools, hospitals and primary healthcare centers. Commercial centers and factories also were destroyed.

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