In a rare apology to the United Nations, Israel said its forces had struck a U.N. compound in Gaza with tank fire. A Bulgarian aid worker was killed.

The R&B singer’s outspoken support for Palestinians had drawn criticism on the campus and beyond. Some students expressed disappointment at the cancellation.

Israel was keeping up its intense bombing campaign in the enclave, which has exacted a heavy price on civilians struggling to find safe places to shelter.

Her career at Israel’s national intelligence agency included working undercover before serving as deputy under three directors.