GAZA CITY (CNN) -- Israel bombed a Hamas government compound early Tuesday, leveling at least three structures, including the foreign ministry building, eyewitnesses and Hamas security sources told CNN. Relatives mourn three boys from the same family who were killed in an Israeli airstrike Monday in Gaza. A Gaza-based journalist, whose name was withheld for security reasons, told CNN he heard 18 blasts in the area and that two fires were burning at the compound early Tuesday. More bombs continued to drop over Gaza through the morning. With Tuesday's bombs, Israel appeared to extend its airstrike campaign in Gaza to a fourth day. The strikes -- which Israel says are aimed at stopping the firing of rockets from Gaza into southern Israel -- have killed more than 375 Palestinians, most of them Hamas militants, Palestinian medical sources said Tuesday.
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Israeli bombs level Hamas foreign ministry, two other buildings, source says
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Barak: Israel in 'all-out war' with Hamas
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Tehran declares day of mourning as protests erupt in Europe, Mideast
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Israel, Hamas blame each other for violating Egyptian-brokered cease-fire
"While recognizing @placeholder's right to defend itself, I have also condemned the excessive use of force by Israel in Gaza.