Tel Aviv: Israeli airstrikes in the Gaza Strip have killed two terrorist commanders, reported The Wall Street Journal (WSJ).

Palestinian militants fired more rockets at Israel, killing an Israeli civilian, a 70-year-old man, the first fatality inside Israel during a current wave of fighting, on Thursday, as fighting between Israel and the US-designated terrorist group persisted for the third consecutive day.

Palestinian militants launched unrelenting rocket barrages into Israel throughout the day.

Rocket struck an apartment block in the central Israeli city of Rehovot, killing a 70-year-old man, the MADA rescue service said. It said four others were moderately wounded.

Earlier Thursday, Israeli military pressed ahead with its strikes against the Islamic Jihad militant group and said a senior commander in charge of the group's rocket launching force, Ali Ghali, was killed when his apartment was hit.

"Ali Ghali... commander of the rocket launch unit... was assassinated in the south of the Gaza Strip along with other martyrs," said a statement from the Al-Quds Brigades, the armed branch of the group.

Later in the day, Israel said it killed another Islamic Jihad commander who was meant to replace Ghali in southern Gaza. Islamic Jihad confirmed the man, Ahmed Abu Deka, was one of its commanders.

The Israeli Defence Force said Abu Deka "had a significant role in commanding and carrying out the rocket barrages toward Israel" over the past day.

Speaking to reporters after the latest airstrike, the head of the IDF Southern Command, Maj Gen Eliezer Toledano, said the military would continue with targeted killings of members of Islamic Jihad, reported The Times of Israel.

"We started with the [senior] command in the opening strike. From there we continued for a second attack last night where we killed the head of the rocket array. And now we killed his deputy," Toledano said.

Toledano said both Ghali and Abu Deka were "responsible for the rockets" during the current escalation, as well as over the past few years.

The Health Ministry in Gaza said a total of 28 people have been killed since the fighting erupted. Among the dead were at least nine Islamic Jihad militants, 10 civilians and nine others, including four whom Israel says were killed in failed rocket launches, whose affiliation remained uncertain, reported ABC News.

Operation Shield and Arrow, as it is known in the military, was launched early Tuesday with the killing of three top Islamic Jihad commanders in the wake of rocket fire from Gaza earlier this month.

Egypt and the United Nations continued to seek a cease-fire between the two sides, Israeli and Palestinian officials said. But those efforts appeared to be stymied in part over Islamic Jihad's demand that Israel cease its policy of targeted killings, officials familiar with the talks said, reported WSJ.