The worst violence between Israelis and Palestinians in seven years intensified on Saturday, as an Israeli airstrike destroyed a prominent high-rise building in Gaza City that housed media outlets including The Associated Press and Al Jazeera.
The Israel Defense Forces said its fighter jets struck the media tower because it also contained military assets belonging to Hamas. The I.D.F. said it had provided advance warning to civilians in the building to allow evacuation.
The attack followed an Israeli airstrike overnight that killed at least 10 members of an extended family in a refugee camp in Gaza, after which Hamas militants aimed another round of rockets at Tel Aviv.
The attacks occurred after a senior American envoy, Hady Amr, arrived in Jerusalem to help broker a cease-fire. Mr. Amr, the United States deputy assistant secretary of state for Israel and Palestinian affairs, was scheduled to meet with senior Israeli and Palestinian officials in Jerusalem and the West Bank.
American, Egyptian and Qatari attempted to negotiate a pause in fighting.