The attack was the second by Israel in three days.
Two Palestinians were wounded in the Thursday night strikes, the WAFA Palestinian news agency reported.
The air attacks targeted a weapons manufacturing plant and a weapons storage facility, the Israeli military said.
Witnesses in Gaza cited by the New York Times said F-16 jet fighters hit an open space in northern Gaza City and a training facility south of the city.
"The manufacturing of rockets in Gaza has no other purpose except to target Israel and its sovereignty putting thousands of lives at risk," Israeli military spokesman Lt. Col. Peter Lerner said in a statement.
Israeli forces remained on high alert along the Gaza border in case of an escalation, the Jerusalem Post said.
The airstrikes came after two rockets landed near the Israeli coastal city of Ashkelon Thursday -- one shortly after midnight and the other Thursday evening.
Both rocket attacks landed in open fields and caused no injuries or damage, Israel said.
Israel struck Gaza Tuesday after a Palestinian sniper fatally shot an Israeli repairing a security border fence.
The airstrikes and tank and infantry fire killed a small child in Gaza and wounded several of her relatives, Palestinian officials said.
Hamas has governed the Gaza Strip since June 2007.
"We will strike those who attack us along with those who sponsor them," Netanyahu said in at an air force graduation ceremony hours before the evening attack.
"There will be no immunity for anyone," he said.
Hamas had no immediate response.
The increased violence comes midway through U.S.-brokered peace talks between Israel and the Palestinian Authority.
Israel is expected to release 26 long-serving Palestinian prisoners -- the third of four promised releases -- Sunday. It is also expected to couple the release with an announcement of further construction in Jewish settlements in the West Bank -- a move Palestinian leaders have said threatens the viability of the talks.
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