Militants in Hamas-ruled Gaza bombarded southern Israel with rockets on Thursday and Israel pounded back with air and ground fire, killing a militant leader and his wife as the deepening violence pushed peace efforts to the sidelines.
Israeli Prime Minister Ehud Olmert vowed to keep striking against what he called the "intolerable" assaults on southern Israel.
Twenty-five Palestinians, including the son of Gaza's Hamas strongman, have been killed since the violence escalated Tuesday. A foreign volunteer on an Israeli border farm was killed by a Hamas sniper.
Hamas, the Islamic militant group that rejects Israel's right to exist, has intensified its direct involvement in the assaults on Israel since the clashes escalated. The group, which had let other militant factions take the lead in attacking Israel since it wrested control of Gaza in June, claimed it fired 30 rockets by midday Thursday, after launching 79 rockets and mortars on Wednesday.
Other groups said they fired an additional four rockets and eight mortar rounds.
Israeli police said 18 rockets and mortars landed in Israel by midday. One rocket slammed into the side of a house, slightly injuring two people, police said.
Israeli forces struck back at northern Gaza from the air and ground, targeting rocket squads and areas militants frequently use to fire projectiles. A leader of the small, Hamas-allied Popular Resistance Committees, Raed Abu el-Foul, and his wife were killed when a missile fired from the air hit their white sedan, Dr. Moaiya Hassanain of the Gaza health ministry said.
Israel said it targeted a vehicle carrying militants from another faction, Islamic Jihad.
Olmert: 'We will continue to fight'
Olmert said Israel would not stand for the continued rocket fire by Gaza militant groups.
"We will continue to fight the (Islamic) Jihad, Hamas and all their allies without compromise, without concessions and without mercy," he told a business conference in Tel Aviv.
Earlier in the week, Olmert suggested that Israel would not embark upon a broad military operation in the coastal strip. Past large-scale strikes have caused heavy Palestinian casualties without halting the rocket fire.
Militants have launched some 4,000 of the crude rockets and mortar rounds at southern Israel since Israel evacuated Gaza in the summer of 2005 after a 38-year occupation. The rockets have killed 12 people since 2001 and sown panic in border areas, where people are frequently forced to rush to take cover when sirens alert them to incoming projectiles.
Militants have been extending their reach as well, with one Iranian-made rocket recently traveling some 10 miles inside Israel's borders.
Israeli Vice Premier Haim Ramon expressed confidence on Thursday that the military strikes, combined with stiff economic sanctions that Israel and the international community have imposed on Gaza, would have the desired effect.
"We already see Hamas wanted a cease-fire," he said. In recent weeks, Hamas had sent out feelers to Israel about a cease-fire, but Israel rejected them.
Hamas' supreme leader, speaking from his base of exile in Damascus, said Wednesday that Israeli raids on Gaza made the group less likely to negotiate any truce with Israel.
Khaled Mashaal also said the military action would hurt chances of Hamas' releasing an Israeli soldier it has held captive since 2006, Cpl. Gilad Schalit.
"What you are doing will deny you of any plan you could be betting on: No exchange for Gilad Shalit and no truce," Mashaal told a news conference.
Mourners demand revenge
At the funeral of two militants killed Wednesday in an Israeli airstrike, mourners demanded revenge and vowed the armed struggle against Israel would continue.
"We mourn our comrades today, but vow to God that the march of resistance will not stop," said Abu Attaya, spokesman for the militants' faction, the Popular Resistance Committees. "Our rockets will rain on the Zionist colonies around Gaza, and our fighters will continue to defeat the occupiers until we achieve our goals. "
The deepening violence has clouded the resumption of Israeli-Palestinian peace talks. On Wednesday, Palestinian President Mahmoud Abbas, Hamas' bitter rival and Israel's moderate partner in newly resumed peace talks, denounced what he called the Israeli "massacre" in Gaza.
He also took the extraordinary step of calling his foe Mahmoud Zahar, Gaza's most powerful Hamas leader, to express condolences for his son's death in a clash with Israel on Tuesday. Shortly after his son was killed, Zahar accused Abbas of complicity by negotiating with Israel.
In Jordan on Thursday, parliament's lower house denounced the "continuous Israeli attacks on the Palestinian territories," the official Petra news agency reported.