Another man the military said played a central role in that attack on Monday was severely wounded in the Israeli strike, the military said in a statement.
Israel carried out at least eight airstrikes against militant squads and sites in Gaza overnight and on Wednesday, and Palestinian groups — including the armed wing of Hamas, the large Islamic group that governs Gaza — fired barrages of rockets from Gaza into southern Israel.
Hamas joined in the latest round of fighting after a break of more than a year during which the group largely adhered to an informal cease-fire, raising fears of a possible escalation into a broader conflict with Israel. So far, though, the confrontation seems to have remained relatively contained, with the Gaza groups firing mostly short-range rockets that do not reach the major cities of southern Israel.
Medical officials in Gaza said that a teenager, Momen Al-Adan, 14, was killed on Wednesday and his father seriously injured in what residents described an Israeli airstrike in southern Gaza City. The Israeli military did not have any immediate comment.
A military spokeswoman said more than 30 rockets had landed in Israel on Wednesday, bringing the total number of rockets and mortar shells fired into Israeli territory since Monday to nearly 80. One rocket damaged a house in an Israeli village near the border with Gaza on Wednesday but caused no casualties.
Lt. Gen. Benny Gantz, chief of staff of the Israeli Army, said on Wednesday that the action taken by his soldiers had prevented a larger attack along the border with Egypt. Faced with threats like that and the rocket fire from Gaza, General Gantz said, the Israeli military is “strong and powerful” and “prepared to respond to any threat at any time.”
The military described the two men targeted on Wednesday as terror operatives who subscribed to a jihadist ideology that puts fighting for Islam ahead of Palestinian nationalist goals. It said that the injured man, Mohammed Rashwan, a resident of Rafah in southern Gaza, was a member of the Tawhid and Jihad organization and that he had been involved in weapons transfers, firing rockets and mortar shells at Israel, and smuggling terror operatives in and out of Gaza.
The man who was killed, Ghaleb Armilat, had assisted Mr. Rashwan in planning Monday’s attack, according to the military.
There was no immediate confirmation from Gaza of the military’s claims. But among the dozens of friends of Mr. Armilat who gathered at the Abu Yousef Al-Najjar hospital in Rafah City, which borders Egypt, were a number of Salafis, or radical Islamists, distinguished by their Pakistani-like clothing and long beards.
Tawhid and Jihad is a shadowy radical Islamic group in Gaza, believed to be inspired by the ideology of Al Qaeda.
The group first surfaced in Gaza in 2007, when it claimed to have kidnapped and killed Alan Johnston, a BBC correspondent. Mr. Johnston was later released alive.
In April 2011, the group said it had kidnapped an Italian citizen in the Palestinian territory and threatened to execute him unless Hamas released the group’s imprisoned leader by a set deadline. Tawhid and Jihad released a video, similar to those released by extremists in Iraq and Afghanistan, that it said showed the hostage.
The Hamas police then stormed a house where they thought the Italian man, Vittorio Arrigoni, a pro-Palestinian activist, was being held. After a clash with his abductors, they found his body. The police said he had been hanged.
The Gaza leader of Tawhid and Jihad, Hisham Saidani, had been arrested by Hamas’s forces earlier in 2011.
On Tuesday, a previously unknown jihadist group calling itself the Shura Council of the Mujahedeen in the Environs of Beit al-Maqdes (Beit al-Maqdes refers to Jerusalem) released a video claiming responsibility for Monday’s attack.
The Israeli military had said two of the assailants were killed in a clash with Israeli forces when Israeli gunfire detonated explosives carried on one of their bodies. The video presented two men who it said were on a suicide mission. It said one was a citizen of Saudi Arabia and the other an Egyptian citizen.
It was impossible to verify the claims made in the video. But Israeli security officials and experts have expressed increasing alarm about what they describe as the growing operations of radical Islamic groups in the Sinai Peninsula and their possible links with Gaza.
Fares Akram contributed reporting from Gaza.