Israel has carried out more air strikes in Gaza, after Palestinian militants fired at least two more rockets at the Israeli town of Sderot early Tuesday.
There were no reports of casualties from the attacks.
Palestinian officials say Israeli air strikes destroyed a metal foundry and another nearby building. Israel says it hit a weapons factory and a militants' command center.
Meanwhile, Israeli Deputy Defense Minister Ephraim Sneh has warned that if the rocket attacks continue, top Hamas leaders, including Palestinian Prime Minister Ismail Haniyah, could be in danger.
Sneh made the threat during an interview with Israeli radio today, a day after a rocket fired from Gaza killed an Israeli woman in Sderot.
Israeli officials say nearly 20 rockets were fired on Israel Monday.
Palestinians say at least four Islamic Jihad militants were killed in Israeli air strikes in the northern Gaza
Nearly 40 Palestinians have been killed since Israel began its campaign last week.
U.N. Secretary-General Ban Ki-moon called the rocket attacks "completely unacceptable" and a violation of international law. But he called on Israel to ensure that its actions do not target civilians or put them at risk.
Mr. Ban also urged rival Palestinian factions Hamas and Fatah to abide by the ceasefire they reached on Saturday after a week of deadly factional fighting in the Gaza Strip.
Some information for this report was provided by AFP, AP and Reuters.