Israel killed three members of a Gazan family in a botched air strike on Wednesday and shot dead a West Bank militant leader a day after Palestinians said some of the worst violence since late 2006 could hurt peace moves.
As Palestinians held a general strike over Israel's killing on Tuesday of 18 people, most of them armed men, an Israeli missile aimed at Islamic Jihad militants in Gaza hit the wrong car and killed three civilians, including a 13-year-old boy.
This week's escalation in violence follows the launch of the most ambitious Middle East peace talks in seven years and a visit by US President George W. Bush to shore up efforts for a deal on Palestinian statehood within a year.
Underscoring the obstacles Bush's peace drive faces, a right-wing party quit Israeli Prime Minister Ehud Olmert's government on Wednesday, condemning the talks and leaving him more politically vulnerable.
In Gaza, body parts were strewn around the twisted metal of a car wreck after the air strike, and the boy's blood-smeared shoes lay tossed to the side. Witnesses and medics said the strike killed three members of the same family. An Israeli army spokeswoman said the missile hit the wrong car and was investigating the incident.
Israeli troops also killed Islamic Jihad leader Walid Obeidi in a gunfight near the northern West Bank city of Jenin, Palestinian witnesses said. Senior Hamas leader Mahmoud al-Zahar, whose son was killed in Tuesday's fighting, said the Islamist group would keep up its fight against Israel.
Israel's Olmert also faces domestic opposition to peace talks, and had his support in the 120-member parliament cut from 78 seats to 67 after right-wing party Yisrael Beitenu bolted from his fractious coalition on Wednesday. But Olmert said the loss would not deter him from continuing to pursue a peace agreement with Abbas, saying negotiations held "the only real chance of ensuring the peace and seucrity of Israeli citizens".