Since Operation Cast Lead, Gaza and Israel have exchanged periodic and sporadic fire. Over the last week, Israeli Prime Minister Benjamin Netanyahu warned that there might be an “escalation” if rockets continued to target Israeli communities.

Israeli Interior Minister Eli Yishai said an operation in Gaza was unavoidable after thousands of rockets hit southern Israeli cities such as Sderot.

“If they can’t sleep in Sderot, they won’t sleep in Gaza. No country would allow over a million of its citizens to spend their days in shelters,” Yishai said.

Maj. Gen Dan Harel, the former deputy head of the Israel Defense Forces, said Israel had decided to take action after Hamas tried to change the “rules of the game.”

“We saw them bringing in new weapons, and using new weapons such as guided missiles and other systems that we could not tolerate,” he said.

Earlier this month, militants in Gaza also fired an anti-aircraft missile at an Israeli helicopter, as Israeli intelligence officers warned that more advanced weaponry was making its way into Gaza via the Sinai peninsula.

Israeli news networks aired footage Wednesday night of militants in Gaza preparing to fire what IDF officials said were Iranian-made Fajr missiles into Israel. The footage, which the IDF provided, was aired as evidence that Israel was trying to knock out Hamas’ ability to strike into central Israel with long-range missiles.

IDF spokeswoman Lt. Col. Avital Leibovich said Jabari had long topped Israel’s most-wanted list. Israel blames him for a string of attacks, including the kidnapping of Israeli soldier Gilad Shalit in 2006. Jabari was also the man who handed Shalit over to Israel in a prisoner exchange last year.

Hamas leaders vowed to avenge Jabari.

“The occupation has opened the gates of hell on itself,” said a statement from the Qassam Brigades, which vowed that its militants would “continue the path of resistance.”

Israeli army officials, including Maj. Gen. Harel, said they feared a “multi-front war” and that they were watching closely for additional reaction from Egyptian President Mohammed Morsi. Former Egyptian President Hosni Mubarak quietly supported Israel’s operations in Gaza, sealing off the Rafah border crossing.

Morsi’s political allies, the Muslim Brotherhood’s Freedom and Justice Party, denounced the Israeli airstrikes Wednesday as a “crime that requires a quick Arab and international response to stem these massacres.”

McClatchy special correspondent Amina Ismail contributed to this report from Cairo.