Palestinian militants killed a pregnant Jewish settler and her four young daughters as Israel's Likud party voted on proposals to pull out of Gaza.
Israeli President Moshe Katzav attended the funeral
Two gunmen ambushed Tali Hatuel's car as she was driving from her Gaza settlement to Israel for the vote.
They struck at virtually point-blank range, shooting the vehicle's occupants repeatedly, Israeli witnesses said.
The killings may have hardened some Likud voters against Prime Minister Ariel Sharon's disengagement plan.
Israeli soldiers shot dead both of the gunmen, whose attack was later claimed by
an alliance of two Palestinian militant groups, Islamic Jihad and the Popular Resistance Committees.
Two Israeli soldiers were lightly injured in the fighting, which took place near the Kissufim crossing between Gaza and Gush Katif.
Soon after the attack, Israeli helicopter gunships attacked a building in Gaza City housing a radio station with Hamas links. Another strike in the West Bank city of Nablus killed four Palestinian militants.
Mrs Hatuel, 34, was eight months pregnant when she died. Also killed were her daughters Hila, 11, Hadar, 9, Roni, 7, and Merav, 2.
Mrs Hatuel had been planning to campaign against disengagement and her bullet-riddled car carried stickers with messages such as "Uprooting the settlements - a victory for terror".
No casualties were reported in the strike on Gaza City
Her husband, David Hatuel, wept at the funeral of the five in the Israeli town of Ashkelon, which took place five hours after the attack. He had been away campaigning when the attack happened.
"I am all alone, there is no one left," he said in a whisper among the mourners, calling his daughters his "flowers".
The groups who claimed responsibility said in a statement that they had struck to avenge the assassination of Hamas leaders Sheikh Ahmed Yassin
and Abdel Aziz al-Rantissi.
The gunmen have been identified as Ibrahim Mohammad Hammad, 22, and Faisal Abu Naqira, 26 - both said to be from the Rafah refugee camp.
Palestinian sources in Nablus identified the four militants killed in a car there as members of the al-Aqsa Martyrs Brigades group.