Cairo: Egypt is installing a series of metal sheets some 60 feet deep along its border with Gaza in an attempt to block tunnels that serve as a key conduit to bring weapons into the Palestinian territory, border guards and area residents said on Thursday.

The work poses a risk to Egypt's relations with Hamas and could undermine its role as a regional mediator.

Egypt is already under fire from Arab and Muslim groups for cooperating with Israel in its two-year blockade of the impoverished territory, with 1.4 million residents.

The border project appears to be one of a series of measures Egypt has taken, some of them in cooperation with the US, to crack down on smuggling since the end of Israel's war on Hamas last winter. The tunnels were a main target of Israel's offensive.

"We in Hamas can't believe that Egypt would put barriers between us," Hamas lawmaker Yehiye Moussa told The Associated Press. "We know that Egypt is under American and international pressure, but we hope that this is not true. We demand that Egypt open its border."

But the tunnels also create an issue for Egypt, allowing terrorists to slip into the country from Gaza and attempt attacks.

Residents along the border said in recent weeks they have seen Egyptian construction crews clearing a corridor along the frontier, then drilling deep holes. They said the workers then filled the trenches with sand.

The residents spoke on condition of anonymity for fear of reprisal.