AFP/Jerusalem

Israel resumed a punishing air campaign against Gaza on Tuesday after its Islamist foe Hamas rejected a six-hour truce and fired dozens of rockets over the border.

The renewed strikes killed one person in southern Gaza, raising the toll in eight days of violence to 193, medics said.

In an early morning vote, Israel's security cabinet said it would accept an Egyptian ceasefire plan which went into effect at 0600 GMT, despite Hamas rejecting the initiative.

But the calm was short-lived, with sirens sending tens of thousands running for cover along Israel's Mediterranean coast as militants fired rockets at the densely populated plain.

The truce proposal, which Cairo laid out late Monday, won US support, but Hamas, whose militants have fired more than 1,000 rockets into Israel, ruled out any end to the fighting without a full agreement.

One Hamas leader said the movement had not yet formulated an official position on the proposal, but rockets continued to be fired after the 0600 GMT deadline.

By 1200 GMT, Israel announced it was resuming its operation.

Tensions were also high on Israel's other borders.

Overnight, three rockets hit in and around the southern resort city of Eilat wedged between Jordan and Egypt.

Another fired from Lebanon struck just outside the northern coastal town of Nahariya, the army said.

A rocket fired from the Syrian Golan Heights also struck the Israeli-occupied sector of the strategic plateau, prompting the air force to launch a pre-dawn strike, killing four people, the Syrian Observatory for Human Rights said.

As the violence resumed, Israeli Prime Minister Benjamin Netanyahu warned Hamas that the Jewish state would not hesitate to resume its punishing campaign in and around Gaza.

- Gaza demilitarisation -

"We responded positively to the Egyptian proposal to give a chance to deal with the demilitarisation of Gaza," Netanyahu said, referring to Hamas's arsenal of missiles and rockets.

"But if Hamas doesn't accept the ceasefire proposal -- and that's how it seems at this point in time -- Israel will have all the international legitimacy to broaden its military activity in order to achieve the necessary quiet."

Cairo's initiative was made after Washington warned Israel against a launching a ground offensive in Gaza, where troops and armour have massed along the border.

"We are encouraged that Egypt has made a proposal to accomplish this goal that we hope can restore the calm that we are seeking," said US President Barack Obama, as Secretary of State John Kerry warned of the "great risks" of any new escalation.

German Foreign Minister Frank-Walter Steinmeier also urged Hamas to accept the Egyptian proposal, accusing the Islamists of holding the people of Gaza "hostage".

And Israeli President Shimon Peres said a ceasefire must mean an end to rocket fire on Israel.

"We all wish to lower the flames, we want an end to the fighting and we hope to see it soon. But there can be no compromise with terror. A ceasefire must be on these terms -- no more rockets, no more terror."

But Turkish Prime Minister Recep Tayyip Erdogan put the blame entirely on Israel accusing it of carrying out "state terrorism" and a "massacre" of Palestinians in Gaza.

- 'Respond with force' -

Israel's security cabinet approved the Egyptian proposal by six votes to two, ordering the military to halt its fire.

"Israel's leadership has directed our forces to suspend strikes in Gaza," the army tweeted. "If Hamas fires at Israel, we will respond with force."

On the ground, Gaza's streets were a little busier than in previous days, with people taking advantage of the unilateral ceasefire to escape their homes and stock up on provisions.

Overnight, a Hamas official said there would be no truce without a fully-fledged deal, and hours later, the movement said it had not been consulted.

"Because we were excluded from the consultations for this (truce) initiative, we are not obliged to abide by it," a statement said.

However, a top Hamas official said the movement had not yet formulated a position on the proposal.

"We're still in consultations. The movement has yet to take an official position on the initiative," Mussa Abu Marzuk, Hamas's Cairo-based deputy leader, wrote on Facebook.

Israel launched Operation Protective Edge before dawn on July 8, hitting Gaza with an intensive air and artillery bombardment aimed at stamping out rocket fire.

Militants answered with over 1,000 rockets, dozens of which have targeted central and even northern Israel.

So far, the conflict has claimed 193 Palestinian lives, with human rights groups saying well over two-thirds were civilians.

Over the same period, 922 rockets have struck Israel, and 207 have been shot down, the army said.

There have been no deaths in Israel, although four people have been seriously wounded.