Israeli aircraft attacked suspected weapons factories throughout the Gaza Strip early on Monday, pushing forward with an offensive against Palestinian militants despite a pledge by a top Hamas leader to halt rocket fire against Israel.
The airstrikes knocked out power to the eastern part of Gaza City and caused damage to several buildings, but no injuries were reported.
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.
The fighting came before a key vote on Monday in Israeli Prime Minister Ariel Sharon's Likud Party. The party's decision on when to hold a primary election 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 had been sabotaged by Sharon's opponents.
Israel, which completed its withdrawal from Gaza two weeks ago, launched its offensive over the weekend following a rocket barrage from the coastal territory into nearby Israeli towns.
It has carried out a series of airstrikes, killing four militants and destroying several weapons facilities, and arrested more than 200 Palestinians.
The fighting has destroyed the atmosphere of goodwill left over from the Gaza pullout and increased already intense pressure on Palestinian leader Mahmoud Abbas to confront militants.
Today's attacks struck targets around Gaza City as well as the southern towns of Rafah and Khan Younis, the AP reports.