Gaza health official Adham Abu Salmia said three Palestinians were wounded in the airstrikes. A 16-year-old girl told Israel Radio she was slightly wounded by shattered glass in the rocket blast.
The violence was the latest sign of escalating tensions along the Gaza-Israel border, where five militants were killed Saturday in the deadliest Israeli assault in the coastal strip in months.
In testimony Tuesday before parliament's foreign affairs and defense committee, Israel's military chief, Lt. Gen. Gabi Ashkenazi, described the situation as potentially "fragile and volatile."
"We have no guarantee the situation won't deteriorate," Ashkenazi said, adding that Israel operates in Gaza for the most part along the border area. Militants routinely attack Israeli soldiers in that area, fire rockets and mortars from there or try to infiltrate Israel by slipping past a barrier.
Ashkenazi also reported that the overnight airstrikes targeted militants from Gaza's ruling Hamas movement for the first time since Israel's war in the Gaza Strip two years ago.
Although Hamas for the most part has refrained from assaulting Israel since then, Israel holds the group responsible for all attacks from the territory. A number of smaller militant groups have continued to fire rockets and mortars into Israel.
Tuesday's airstrikes targeted a weapons-manufacturing facility and smuggling tunnels, the military said. Some of the tunnels were designed to allow militants to infiltrate Israel to carry out attacks, the statement said.
Palestinians said one of the targets was a government-built dairy factory.
The airstrikes - hitting more than double the number of targets ordinarily struck in a single operation - came in retaliation for the firing of 13 rockets and mortars at Israel this week, the military said. Hours later, Palestinian militants fired a rocket into southern Israel, wounding the Israeli teen as she was in her home.
Ashkenazi told the parliamentary panel that a new Israeli system designed to shoot down incoming rockets, known as Iron Dome, would be operational by early 2011, without disclosing where it would be deployed.
His comments were relayed by a meeting participant who spoke on condition of anonymity because the session was confidential.