Shortly afterward, Hamas said it fired a salvo of rockets at southern Israel in response to the airstrike.
Hamas fired rockets toward Jerusalem late Monday, in an apparent attempt to present itself as the champion of the protesters. In the conflict that spiralled from there, Israel says it wants to inflict as much damage as it can on Hamas' military infrastructure in Gaza.
Prime Minister Benjamin Netanyahu vowed that Hamas would "pay a very heavy price" for its rocket attacks. Israel called up 9000 reservists Thursday to join its troops massed at the Gaza border.
An Egyptian intelligence official said Israel had turned down an Egyptian proposal for a one-year ceasefire that Hamas had accepted. The official, who was close to Egypt's talks with both sides, spoke on condition of anonymity to discuss the internal negotiations.
On Friday, the US deputy assistant secretary of state for Israel-Palestinian affairs, Hady Amr, arrived in Israel as part of an attempt by Washington to de-escalate the conflict.
US President Joe Biden gave a show of support to Netanyahu in a call a day earlier, saying "there has not been a significant overreaction" in Israel's response to Hamas rockets. He said the aim is to get a "significant reduction in attacks, particularly rocket attacks".
Hamas has fired some 2000 rockets toward Israel since Monday, according to the Israeli military. Most have been intercepted by anti-missile defences, but they have brought life to a standstill in southern Israeli cities, caused disruptions at airports and have set off air raid sirens in Tel Aviv and Jerusalem.