There were no immediate reports of casualties or comment from the Israeli army.
Earlier on Friday, six Palestinians, believed to be members of the resistance movement Hamas, were killed by Israel in what is seen as a resumption of Israel's policy of "targeted killings".
According to witnesses, Israeli helicopter gunships fired missiles at a vehicle in Gaza, destroying it and scattering body parts of the occupants.
Witnesses said Israeli Apache helicopter gunships had fired three missiles at the car in Gaza.
Aljazeera's Gaza correspondent quoted medical sources at al-Shifa hospital in the Gaza Strip as saying that four Palestinians had been killed by the Israeli helicopter strike.
Five were confirmed dead; five civilians, including a child, were also wounded in the attack, medical sources told Aljazeera.
There was no immediate comment from the Israeli occupation army.
An AFP correspondent in Gaza also saw a headless corpse and the gutted car following the attack.
West Bank attack
In another Israeli attack on Friday, Aljazeera's correspondent in Ram Allah, Shirin Abu Aqla, reported that two Palestinians, Muhammad Aiyash and Muhammad Mirai, were killed and one seriously injured in an Israeli helicopter missile strike in the West Bank town of Salfit, near Nablus.
There was no immediate comment from the Israeli army regarding this attack, either.
Doctors confirmed that four
people were killed in Gaza
The missile strikes were part of a heavy Israeli offensive against Palestinian resistance groups.
As part of the peace deal, reached in February, Israel had promised Palestinians to halt targeted killings, but has now reaffirmed the resumption of its assassination policy against Palestinian resistance groups.
Palestinian Authority leader Mahmoud Abbas has been in Gaza since Thursday for crisis talks with the resistance groups in a bid to rescue the flagging truce.
The Palestinian Authority condemned the Israeli attacks as a "dangerous escalation" and said Israel is trying to destroy its own efforts to impose the rule of law in the occupied territories.
"We strongly condemn the dangerous Israeli escalation. At the same time that the Palestinian Authority is trying to impose the law, Israel wants to destroy all such efforts," chief Palestinian negotiator Saeb Erikat said.
"We strongly condemn the dangerous Israeli escalation. At the same time that the Palestinian Authority is trying to impose the law, Israel wants to destroy all such efforts"
chief Palestinian negotiator
Hamas's military wing, the Izzaddin al-Qassam Brigades, said the four, who were assassinated in Gaza, were Hassem Abu Ras, Adel Hanyiah, Saber Abu Assi and Amjad Arafat.
Israel has threatened to re-occupy Palestinian cities, if necessary, to ensure the safety of Jewish settlers during the "disengagement plan" from the Gaza Strip and four settlements in the northern West Bank.
Meanwhile, Israeli Prime Minister Ariel Sharon announced in a television interview late on Friday that he had ordered the army to take "all necessary measures" against what he said were Palestinian "terrorist organisations".
"I have ordered the army to take all necessary measures," Sharon said.
Asked whether this meant the resumption of targeted killings against Palestinian resistance movements, Sharon said there was "no limit" on the orders handed down to the army.The latest deaths raised the overall toll since the September 2000 start of the second Palestinian Intifada (Uprising) to 4793, including 3720 Palestinians and 998 Israelis, according to an AFP count.