Israel aircraft hit a building at the Islamic University in Gaza city early on Tuesday, Palestinians said. Black smoke rose from the building, set on fire in the attack. There was no immediate word of casualties.
The military had no comment. The University is considered a Hamas stronghold.
Israeli aircraft have been carrying out nightly airstrikes in the city and elsewhere in the Gaza Strip, part of Israel's campaign to try to force release of a soldier captured in a Palestinian cross-border raid on June 25. Earlier targets were the prime minister's office.