Hamas says Israeli warplanes have bombed the Islamic University in the Gaza Strip.
The university is a significant Hamas cultural symbol, but Israel has accused Hamas of using the facilities to develop explosives.
Witnesses in Gaza said they saw six separate air strikes on the Islamic University, hitting a laboratory building, just after midnight.
The BBC reports the university is a centre of support for Hamas. Many of its top officials graduated from there.
Warplanes have also struck Hamas government offices.
Some 298 people have been reported killed since the Israeli offensive began on Saturday morning, the Jewish Sabbath, in retaliation for continuous rocket attacks on Israel.
Hamas ended a six-month ceasefire on 19 December.