About 80 percent of tunnels used by Palestinians to transfer goods into the impoverished Gaza Strip from Egypt are " no longer functioning " due to a crackdown by the Egyptian military, the UN says.

UN Middle East Peace Envoy Robert Serry warned the UN Security Council on Tuesday about concerning life condition in the Gaza Strip which is under a strict blockade imposed by Israel.

The Israeli siege has severely limited flow of basic humanitarian needs to the coastal strip.

" We are concerned that already difficult economic and humanitarian conditions in Gaza will further deteriorate, if access into Gaza through legal crossings of basic commodities like building materials is not liberalized, " Serry said.

He said Gaza was experiencing " some serious shortages of fuel and basic building materials for which the tunnels had become the primary entry point due to severe restrictions on imports via the official crossings and the higher cost of fuel. "

The tunnel crackdown has gathered pace since the Egyptian military removed president Mohamed Morsi from power earlier this month.

Ala Al - Rafati, the Hamas economy minister, said on Sunday that tunnel closures since June had cost Gaza around $230 million - - around one - tenth of the gross domestic product of the territory.

Residents of Gaza are blockaded by land, sea and air by the Israeli regime forces.

Israel’s blockade of Gaza is denying the Palestinian people access to medical supplies and food.

Hospitals face critical shortages, with 40 percent of all essential medicines at zero stock level, according to a report by the Canada - based Global Research.

Out of the 1.7 million Palestinians living in Gaza 54 percent are food - insecure including 428,000 children.

Israel’s illegal blockade has also led to a massive shortage of building materials to repair the homes, hospitals, schools and water / sanitation infrastructure that have been destroyed / damaged by the regime in the last 5 years.

Most of Gaza’s water supplies are polluted and unsafe to drink. There are power cuts every day as well.

The International Red Cross and the United Nations have found the Israeli government’s siege of Gaza to be illegal under international law.

In September 2011, five independent UN rights experts made a report to the UN Human Rights Council which said that Israel’s siege of Gaza amounted to collective punishment of the Palestinian people and was a “flagrant contravention of international human rights and humanitarian law” under the Fourth Geneva Convention.

Prominent political thinker Noam Chomsky has described the Gaza Strip as “the world’s largest open air prison. ”