Despite recent moves by Israel to ease construction in the Gaza Strip, restrictions on building materials are hampering international humanitarian efforts while doing little to impede the Hamas-led government they are designed to weaken, aid and nongovernmental groups say.

Israel says the limits on cement and other imports are intended to prevent misuse by Hamas. But the Islamist militant group has ready access to construction materials through smuggling tunnels along the border with Egypt.

Instead, aid groups say, Israeli bureaucracy and bottlenecks at border crossings are snarling the delivery of materials to international relief organizations struggling to build much-needed housing, schools and infrastructure projects.

"The United Nations, who have a responsibility to help, we're the ones that are held up," John Ging, director of the U.N. Relief and Works Agency's Gaza operations, said in an interview. "We're held up from building schools. We're held up from our other infrastructure projects, from the housing people need. And, yet, for the other parts of society here - be that either those with ulterior agendas or people who just have money - they can get on with it."

After Israeli naval commandos killed nine activists aboard a Turkish-flagged aid ship trying to breach the blockade of the Gaza Strip in May, Israel faced pressure to ease its grip on the territory. Israel pledged to increase the flow of construction materials for projects under international supervision and lifted a ban on the import of most consumer goods, which increased supplies in stores and hurt the black-market economy.

This month, Israel - which recently approved the export of strawberries and flowers from Gaza to Europe - said it would soon allow Gazans to export more produce and some manufactured goods, which could increase the standard of living in the strip and create jobs.

Humanitarian needs persist
But even as Gaza's economy shows signs of improvement, its humanitarian needs remain widespread. Thousands of homes damaged in a punishing three-week war with Israel in 2008-2009 are yet to be rebuilt. Millions of liters of raw sewage are spilling into the Mediterranean Sea because treatment plants remain in disrepair. And experts say Gaza's rapidly growing population of 1.5 million could run out of fresh drinking water by 2015 if the infrastructure is not overhauled.

The number of internationally funded aid projects authorized by Israel increased from 14 before the May naval raid to 78 by June. But Ging says that's only a fraction of what Gaza's heavily aid-dependent population needs. The 27 U.N. projects that have been approved make up just 7 percent of the relief agency's construction plans. Many of the projects that have been approved cannot be completed on time because of the problems getting materials, he added.

Israel evacuated the Gaza Strip in 2005 but still controls what enters and leaves the territory. Tensions have escalated along Israel's border with Gaza in recent weeks as rockets and mortar shells fired from the territory have landed in Israeli towns with increasing frequency.

Such periodic attacks are at the heart of Israel's reluctance to ease restrictions on construction materials, which Israeli officials fear Hamas could use to build bunkers to hide weapons and fire rockets. Construction by Hamas could also boost popular support for the group, which has ruled the Gaza Strip since seizing control of it in 2007.

Securing Israeli approval of projects requires weeks or even months of negotiations and the sign-off of up to six Israeli agencies, according to Gisha, an Israeli nongovernmental group that tracks movement and access problems between Israel and the Gaza Strip.

"Hundreds of hours of staff time and millions of dollars are spent on documenting each nut and bolt - as if we were supervising the transfer of highly specialized weapons, and despite the fact that steel, concrete and gravel enter Gaza quite freely via the tunnels," said Sari Bashi, Gisha's executive director.

Kerem Shalom, the only full-time border crossing for goods, has increased its capacity and can accommodate 250 trucks daily, most of them carrying commercial products. But the problems with construction materials persist. A single conveyer belt at the Karni crossing is used for animal feed and concrete. It operates two days a week, creating shortages of both goods. Israel says it cannot operate the conveyer belt more often because of security problems.

Overall, nearly 150 trucks carrying construction materials enter Gaza each month. Although that marks an increase from what was permitted before the May raid, it is a fraction of the roughly 5,000 per month that entered the territory when trade flowed freely.

A deficit of schools
In Rafah, at the southern tip of the Gaza Strip, there are endless rows of what appear to be greenhouses. But behind the plastic sheeting of one, a steep dirt incline leads to an 800-meter tunnel to Egypt. Bags of aggregate - crushed rock used in the making of cement - are transported by a rudimentary pulley system, bagged and wait to be trucked to market.

Hamas says that with help from Islamic charities in the Persian Gulf region, it is using materials smuggled through these tunnels to build schools and houses. Yasser al-Shanti, director of public works in the Hamas-led government in Gaza, said the cash-strapped group renovated 1,000 houses with the support of such charities. A school has been built in Rafah, and a major street in Gaza City repaired.

Over the past two months, about half of the 925 trucks of supplies scheduled to enter Gaza for U.N. projects actually did, according to the U.N. relief agency, Gaza's largest outside donor.

Since Israel's move in June to facilitate more international construction, the agency has completed two projects - a sewage pumping station and 151 housing units - a fraction of the 10,000 units it seeks to build.

But Ging says his main concern is schools. Israel has approved six out of 100 the agency says it needs to build to accommodate 40,000 eligible children. "Overcrowded classrooms, tens of thousands of children failing academically, all of these things, they have long-term detrimental consequences," he said. "We don't have the luxury to deal with that after the peace process."

Maj. Gen. Eitan Dangot, coordinator of Israel's activities in the Gaza Strip and West Bank, said Israel is examining the agency's requests as quickly as it can and supports its efforts to establish schools.

As for when Israel might eliminate restrictions on construction materials for the private sector, officials say they are considering it. "After a period of quiet from all the shooting . . . maybe it will start happening," said Guy Inbar, a spokesman for Dangot. "But not yet."