Israel will not apologize to Turkey for a deadly May 2010 raid on a Gaza-bound flotilla and will not lift its blockade on the Gaza Strip, an Israeli minister insisted on Wednesday, as ties with Ankara sank to new lows.

"Israel defends its interests and its government will not apologize," said Israel Katz, Israel's transport minister and a member of Prime Minister Benjamin Netanyahu's Likud party.

Israeli war planes bombed an alleged weapons manufacturing site in the central Gaza Strip overnight after a rocket was fired from the Palestinian territory, Israel's army said on Tuesday.

The rocket landed in southern Israel but caused no damage or injuries, the army said. There were no immediate reports from Gaza of injuries from the Israeli strike.

Top diplomats piled pressure on Turkey and Israel to make up Saturday after Ankara's decision to expel the Jewish state's ambassador in retaliation for last year's deadly Gaza flotilla raid.

U.N. chief Ban Ki-moon, senior European foreign ministers and officials in Washington all urged the one-time allies to end their increasingly poisonous dispute that they worried could impact on the wider Middle East.

Egypt's military has started to close smuggling tunnels to Gaza, witnesses said on Saturday, amid Israeli warnings of plans by Gazan militants to attack the Jewish state through Egyptian territory.

Witnesses along the 12-kilometre border with the Islamist Hamas-controlled Palestinian enclave said soldiers had begun using earth-moving equipment to seal tunnel openings with rocks and sand.

Israel will not apologize for its deadly 2010 raid on a Turkish-led flotilla of Gaza aid ships, an Israeli diplomatic source said Friday after a U.N. report accused the Jewish state of using excessive force.

"Israel once again expresses its regrets for the loss of human life but there will be no apology for this operation," the source, who spoke on condition of anonymity, told AFP.

Israel will accept the United Nations report on its deadly attack last year on a Turkish-led flotilla of aid boats for the Gaza Strip with some reservations, a senior official said Friday.

"We will announce our acceptance of the report after its official publication, with specific reservations," the official who declined to be identified told Agence France Presse.

The Palestinian Islamist movement Hamas said Thursday that a U.N.-mandated inquiry into a deadly Israeli raid on an aid flotilla bound for Gaza was "unjust" and lacked balance.

The inquiry into the Turkish-led aid flotilla said Israel's commando raid in 2010 was "excessive," according to extracts published by the New York Times newspaper.

A rocket fired from Gaza on Sunday hit southern Israel in what was the fourth projectile lobbed across the border since a truce took hold two days earlier, Israeli officials said.

The rocket landed near Khatzerim, a village just west of the southern desert city of Beersheva, a police spokeswoman said.

Israel will keep hitting Islamic Jihad if it continues its "terrorist activities" against Israeli targets, a minister warned on Thursday after air strikes on Gaza killed two of its militants.

"We will continue to hit those who hit us. Islamic Jihad, which has an itchy trigger finger, is starting to pay the price," Home Front Defense Minister Matan Vilnai told army radio as a days-old truce appeared to be unraveling.

Seven rockets from Gaza hit Israel on Monday just hours after militant factions agreed an informal truce after four days of deadly cross-border violence in which 15 Palestinians and an Israeli died.

The truce was hammered out after talks with Egyptian officials, and several hours later, Israel's security cabinet held an emergency session during the night at which ministers decided to hold off from further attacks on the Palestinian territory, army radio said.