Palestinian security officials said Israeli helicopters fired rockets at targets in Gaza City and the southern Gaza town of Khan Yunus but could not immediately say what the targets had been in Gaza City and whether there had been any victims.
A building belonging to the Palestinian Authority in Khan Yunus was hit by three rockets, the officials said without giving further details.
An Israeli army spokesman said that aircraft had attacked a road near Bait Hanun in the north of the Gaza Strip "used by terrorists to get to the sectors from where they fire rockets at Israel."
He said a second attack had targeted four installations used by "terrorist organizations to stock arms" at Khan Yunus and Rafah in the south.
The Israeli army said it was pushing forward with an offensive against Palestinian resistance groups.
Jihad leader killed
The attacks came hours a senior member of the Islamic Jihad resistance group was killed by an Israeli air strike.
Muhammad Khalil was riding in a Mercedes along a coastal Gaza road when a missile fired from an Israeli aircraft killed him and his bodyguard.
Muhammad Khalil was killed by
Israelis in their fifth attempt
Witness Atif Qatrous, 22, said he was leaving work when he saw a missile hit the car. One of those inside was decapitated and the other was badly wounded, he said.
The attack was at least the fourth Israeli attempt to kill Khalil in recent years.
Palestinian medical sources said four bystanders were injured in the attack.
Israel continued with its air campaign despite a call by Hamas leader Mahmud al-Zahar to end the group's rocket attacks.
Zahar spoke at a news conference late on Sunday, saying his group remained committed to a seven-month-old cease-fire and that he wanted to prevent further Israeli attacks.
"We call on our military groups to stop their operations against the enemy from the Gaza Strip," al-Zahar said. The Hamas leader also renewed a pledge to end Hamas' military-style parades celebrating the Israeli withdrawal.
But Israeli security officials said they would wait to see whether the Palestinian attacks would in fact halt before calling off the military strike Israel launched over the weekend.
Israeli warplanes have struck
several targets in Gaza
An Israeli air strike early on Monday knocked out power to the eastern part of Gaza City and caused damage to several buildings, but no injuries were reported.
A metal workshop, which the Israeli army said was used by Hamas to make weapons, was also destroyed in the attack.
Factory owner Ali Shaaban said it was the fourth time the workshop had been targeted. Shaaban said he produced engine parts for vehicles and generators, not weapons.
Israeli warplanes also struck unidentified targets around Gaza City as well as the southern towns of Rafah and Khan Yunus, and an access road leading to a rocket-launching site in northern Gaza.
The weekend assaults on Gaza have killed at least four Palestinians, including key resistance leaders, and left dozens injured.
An air strike on Sunday partially destroyed a school and injured 15 people, many of them children.
Children were injured in the
Israeli air strike on a school
The blast struck the al-Arkam school, established by the late founder of Hamas, Shaikh Ahmad Yassin, which is situated in the Tufah neighbourhood - a densely populated area and a Hamas stronghold.
The blast collapsed part of the school and caused damage to at least five nearby homes.
Israeli troops also launched an extensive arrest campaign, netting more than 200 activists from Hamas and Islamic Jihad, Aljazeera learned.
Most of the detainees, among them leading Hamas figures Hassan Yusuf and Muhammad Ghazal, were from Hebron and Ram Allah.
The fighting has destroyed the atmosphere of goodwill left from the Gaza pullout and increased already intense pressure on Palestinian leader Mahmoud Abbas to confront resistance groups.
The latest round of violence surged when a blast on Friday killed 16 people at a Hamas rally in Gaza. One of the victims, a 12-year-old Palestinian boy, died of his wounds on Sunday.
Hamas blamed Israel, and fighters fired rockets at Israeli towns in response, though Israel denied responsibility and the Palestinian Authority said Friday's explosion appeared to be an accident caused by Hamas members carrying explosives.
Palestinian leaders accused Israel of trying to wreck hopes of reviving peace talks that were kindled by the Gaza pullout.
Abbas: Sharon does not want
peace, security or negotiation
Abbas said that if Israeli Prime Minister Ariel Sharon had ordered the army to use full force it meant "he doesn't want peace, or security or negotiations".
But Sharon was on Monday facing a battle of his own.
Sharon's Likud Party is due to decide in a key vote on Monday when to hold primary elections, a political move that is widely seen as a test of Sharon's leadership.
Sharon, under fire from hardliners in the party because of the recent withdrawal from Gaza, walked out of a stormy Likud meeting on Sunday night without delivering his prepared speech after a problem with the sound system prevented him from speaking. Some Likud officials said the system was sabotaged by Sharon's opponents.
PA spokesperson attacked
Meanwhile, an armed group in Gaza attacked the home of the spokesman of the Palestinian Interior Ministry, the agency that oversees Palestinian security forces.
The spokesman, Tawfiq Abu Khussa, was not hurt.
Abu Khussa said the attack was the third attempt on his life in recent days and hinted that Hamas was behind the shooting.
"You can ask those who are spreading rumours of treason," he said late on Sunday.
The group has criticised Abu Khussa and other Palestinian officials for saying negligence caused the deadly blast last week at the Hamas rally in the Jabalya refugee camp.