* Hams rejects ceasefire extension
* Israel keeps focus on militant tunnels in Gaza
* Tensions high in West Bank after deadly clashes
* 1,000 Palestinians killed in Gaza since July 8 (Recasts with ceasefire breaking down)
By Nidal al-Mughrabi and Ori Lewis
GAZA/JERUSALEM, July 26 (Reuters) - Militants resumed firings rockets into Israel from Gaza on Saturday, rejecting an extension to a ceasefire in a conflict in which more than 1,000 Palestinians, mostly civilians, have died.
Israel had agreed to extend an initial 12-hour pause in the fighting by a further four hours but this was rejected by Islamist group Hamas, which dominates Gaza.
Warning sirens sounded across the country as rockets were fired as far as the Tel Aviv area, police said. Israeli tank fire killed a man in the southern Gaza Strip, a local official said, announcing the first fatality after the breakdown of the ceasefire.
Even before the truce broke down, some Israeli ministers signalled that a comprehensive deal to end the 19-day conflict with Hamas and its allies was remote.
Gazans had earlier taken advantage of the lull in fighting to recover their dead and stock up on food supplies, flooding into the streets after the ceasefire began at 8.00 a.m. (0500 GMT) to discover scenes of massive destruction in some areas.
Gaza Health Ministry spokesman Ashraf Al-Qidra said rescue teams had retrieved 132 bodies from wrecked neighbourhoods.
The man killed by tank fire brought the number of Palestinian fatalities to 1,033 since July 8 when Israel launched its offensive, aimed at ending rocket fire out of Gaza.
Israel's security cabinet was meeting to discuss a United Nations request to extend the truce by 24 hours as well as international efforts, being led by U.S, Secretary of State John Kerry in Paris, to secure a more durable ceasefire.
However, speaking prior to the renewed rocket attacks, security cabinet minister Gilad Erdan said a definitive deal looked unlikely, with no representatives from Israel, Egypt or the Palestinian Authority attending the Paris talks.
"I think we are very far from a diplomatic solution. It makes much more sense that we are closer to expanding the military operation," he told Israel's Channel 2 Television.
Kerry, who has been heading international efforts to end the fighting, met the foreign ministers of France, Italy, Britain, Germany, Turkey and Qatar in Paris.
Israel said five more of its soldiers were killed in pre-truce fighting in Gaza, bringing the army death toll to 40 as troops battled militants in the tiny Mediterranean enclave that is home to 1.8 million Palestinians.
Three civilians, including two Israeli citizens and a Thai labourer, have been killed by rockets fired from Gaza.
Israel's and Hamas's positions regarding a long-lasting halt to hostilities remained far apart.
Hamas wants an end to an Israeli-Egyptian blockade of Gaza before agreeing to halt hostilities. Israeli officials said any ceasefire must allow the military to carry on hunting down Hamas's tunnel network that criss-crosses the Gaza border.
Israel says some of the tunnels reach into Israel and are meant to carry out attacks on Israelis. Other underground passages serve as weapon caches and Hamas bunkers. The military said it had uncovered four such tunnel shafts inside Gaza on Saturday.
The Gaza turmoil has stoked tensions amongst Palestinians in East Jerusalem and the occupied West Bank.
Medics said eight Palestinians were killed in incidents near the West Bank cities of Nablus and Hebron on Friday - the sort of death toll reminiscent of previous uprisings against Israel's prolonged military rule there.
The deputy leader of Islamic Jihad militant group that is allied to Hamas said that Egypt's mediation efforts were still being considered but improvements were being sought and, in the meantime, the fight would go on.
"We are still open to the Egyptian initiative and there are hot contacts to improve it ... We are going to pursue the battle until the blockade is ended. The resistance carries our demands," he said in a text message to reporters. (Additional reporting by Noah Browning in Gaza and Arshad Mohammed in Paris and Michelle Nichols in New York; Writing by Maayan Lubell; Editing by Tom Heneghan, Crispian Balmer and Toby Chopra)