GAZA, March 29 (Reuters) - Israel will allow a shipment of clothes and shoes to be delivered to Palestinians in the Gaza Strip for the first time in its almost three-year-old tight blockade of the enclave, Palestinian officials said on Monday.

They said the first 10 truckloads would be arriving via the Israeli-controlled Gaza border point on Thursday.

Israel is under international pressure to relax its blockade, which the United Nations says punishes Gaza's 1.5 million people over their leaders -- the Islamist group Hamas, who are pledged to Israel's destruction.

Israel prohibits shipments of cement and steel to Gaza on the grounds that Hamas could use them for military purposes.

Its long list of controlled goods also includes items that critics say have no apparent military value, such as children's crayons and books.

Gaza has been getting most of its consumer goods via tunnels from neighbouring Egypt operated by smugglers who add on hefty surcharges. Gaza merchants said 10 truckloads would not fill their stocks and demanded that Israel release goods long held in its sea ports.

Egypt is building an underground wall to block the tunnels, which have been frequently bombed by the Israeli air forces since Israel's offensive against Hamas 14 months ago in which some 1,400 Palestinians and 13 Israelis were killed.