Israel carried out a wave of airstrikes on what it said were militant targets in Gaza, leveling a six-story building in downtown Gaza City, and Palestinian militants fired dozens of rockets into Israel early Tuesday, the latest in the fourth war between the two sides, now in its second week.
Explosions from the airstrikes echoed through the pre-dawn darkness in Gaza City, sending flashes of orange across the night sky.
The strikes toppled the Kahil building, which contains libraries and educational centers belonging to the Islamic University.
Clouds of dust hung over the site, which had been reduced to piles of concrete rubble and tangled power lines.
There were no immediate reports of casualties from the overnight strikes.