GAZA CITY (Ma’an) -- Israeli airstrikes killed two Islamic Jihad militants and three civilians on Monday, bringing the death toll since Friday to 23 people, medics and Ma'an's correspondent said.

An airstrike on Monday afternoon in Beit Lahiya killed Muhammad al-Hasoumi, 65, and his daughter, 30, medical spokesperson in Gaza Abu Salmiya said.

Earlier, hospital officials said a 15-year-old schoolboy was killed in a separate air strike during the day on Monday. Nayif Shaaban Qarmout was killed in Beit Lahiya, north Gaza, Ma'an's correspondent said.

Witnesses said that the 15-year-old was playing with friends in a play ground near his school when an Israeli missile hit the area.

Five others were injured and taken to Shifa hospital in Gaza City.

Early Monday, two Islamic Jihad militants, Raafat Abu Eid, 24, and Hamadah Salman Abu Mutlaq, 24, were killed in Khan Younis, Ma'an's correspondent said. Abu Eid was killed when an airstrike targeted a vehicle he was traveling in.

Two other militants sustained injuries and a female passerby was also injured in the attack.

Abu Mutlaq, 24, was killed near a mosque in a village east of Khan Younis after warplanes fired at him. Three others were injured and taken to hospital for treatment.

Earlier, Israeli airstrikes had hit two homes in the northern Gaza Strip, injuring 33 civilians, most of whom were women and children, Abu Salmiya said.

Most sustained moderate injuries, with one critically injured, and were transferred to hospital.

A 17-year-old girl and another man were also injured as Israeli missiles struck a home in Gaza City, Abu Salmiya said.

An Israeli military spokeswoman said aircraft had carried out six strikes on Monday. At least 20 rockets have been fired at Israel on Monday, she said.

The army targeted "a weapons storage facility and four rocket launching sites in the northern Gaza Strip, as well as a rocket launching site in the southern Gaza Strip," a statement said.

Israel's army denied, however, that there had been any military activity in the northern Gaza Strip at the time of 15-year-old Nayif Shaaban Qarmout's death.

Gaza's Prime Minister Ismail Haniyeh said late Sunday that neighboring Egypt was working to stop the violence and was consulting with militant factions but added that Israel would have to first stop its air strikes.

The latest round of violence flared on Friday when an Israeli airstrike killed two militant leaders in Gaza.

Israel accused them of planning a cross-border attack via Egypt, although an Egyptian official said Sunday that the Sinai is "fully under control."

"This is an attempt by Israel to give justification for the offensive against Gaza," he said.

On Sunday, PLO official Hanan Ashrawi strongly condemned Israel's latest military escalation.

"The Israeli government has acted with impunity for its unilateral violations for far too long. The illegal, cruel siege of the Gaza Strip, along with all other violations of international law must come to an end."

The PLO official called on the international community to take serious measures to halt Israel's policy of extrajudicial executions and the continued killing of innocent civilians.