An Israeli air strike in Gaza City has killed at least 11 people and wounded more than 30.
Palestinian medics say nine civilians, including two children, were among the dead. Israel says its aircraft attacked a van carrying Palestinian militants on their way to fire rockets into southern Israel.
A top rocket launcher for the Islamic Jihad was reported killed in the strike.
Palestinian President Mahmoud Abbas denounced Israel's attack as "state terrorism," and he called on the international community "to put an end to Israeli aggression."
Meanwhile, Israel has denied responsibility for an explosion last week on a beach in the Gaza Strip that killed eight Palestinian civilians.
An Israeli military inquiry found the blast was caused by an explosive buried in the sand on the beach -- not by Israeli artillery or Israeli Navy vessels firing from offshore.
Palestinian officials have rejected the conclusions, blaming the blast on Israel.
Israel has been firing missiles and artillery at suspected Palestinian militants who are launching rockets at the Jewish state from the Gaza Strip.
At first, media reports said Friday's explosion was from an errant Israeli shell.
The bloodshed today was much greater than from most other retaliatory attacks.