Israeli warplanes struck three targets in the Gaza Strip on Friday in response to militant rocket and mortar fire, the Israeli army said.
At least four people, three women and a boy, were hurt in one attack in the central Gaza Strip when an uninhabited building close to where they were standing collapsed after being hit, local residents said.
The injuries were not considered to be life threatening, a Gaza hospital source said.
The two other strikes were aimed at targets near the town of Khan Younis in the southern part of the territory, one of which was a training camp belonging to the Islamic Jihad militant group. There were no reports of casualties.
An Israeli military spokesman said three air strikes had been carried out against militant targets in the coastal strip.
"Two of the three targets were smuggling tunnels that were being built and they were destroyed," said the spokesman, who declined to specify the nature of the third target.
He added that nine mortar shells and one longer-range rocket were fired over the past 24 hours, the highest number in a concentrated period for several months.
The Popular Resistance Committees, a Palestinian militant group, claimed responsibility for the mortar fire, saying it was in retaliation for Israel's killing of two militant leaders of the al-Qaeda linked Army of Islam in Gaza on Wednesday.