Reporting from Jerusalem — Clashes between Israel's military and Gaza Strip militants continued for a second day Friday, killing nine Palestinians — four civilians and five militia fighters accused by Israel of launching rocket attacks, officials said.
Israel's military launched several air attacks against targets throughout Gaza, saying it was retaliating for continuing rocket and mortar strikes against southern Israeli cities over the preceding 48 hours. Most of the projectiles fired by Gaza militants were destroyed or landed in open space, but one antitank missile Thursday critically injured a teenage Israeli boy in a school bus.
"Red lines were crossed," Israeli Maj. Gen. Tal Russo, who is in charge of the southern command, said on Israel's Army Radio.
Some Israelis and Palestinians expressed fear that the worsening violence could escalate into the start of another Israeli ground offensive, similar to the 22-day Operation Cast Lead that began in December 2008 and killed about 1,400 Palestinians.
"We are scared," said Jamal Abdul Ghani, who lives 800 yards from the border with Israel.
Gaza hospital officials said late Friday that 14 Palestinians had been killed since Thursday, including two children and a woman who were mistakenly hit during the Israeli airstrikes.
Hamas, the militant Islamic group that controls Gaza, did not respond to a request for comment.
In a statement, Israel's military blamed militants for the civilian deaths, saying they "were firing mortar shells from the heart of a civilian neighborhood."
Israeli officials have said they do not believe that leaders of Hamas want another major clash. Late Thursday, the group tried unsuccessfully to organize a cease-fire.
"I believe they are still deterred," said Israeli Vice Prime Minister Moshe Yaalon this week. "Hamas doesn't want to pay the price."
At the same time, Israeli military officials speculated that Hamas might be losing its grip on power in Gaza to other, more radical groups, such as Islamic Jihad.
Former Israeli government advisor Raanan Gissin said Friday that Syria, Iran and other enemies of Israel might be trying to spark another conflict to distract attention from popular unrest in their own countries.
"No doubt [those responsible for firing rockets] really want to drag Israel back into the equation … and refocus the rage back against Israel," Gissin told the Israel Broadcasting Authority on Friday. "There could be an inadvertent escalation."
Yiftah Shapir of Israel's Institute for National Security Studies said in an interview that it remained unclear whether the clashes would escalate into another ground assault. He said the security threat was not as severe as it was in 2008.
"It might be tempting to do the same thing we did in 2008 to keep up our deterrence, but the situation right now, as grave as it is, is not as bad as December 2008," Shapir said. "The question now is not really military. It's more political than anything else."
The United Nations and the European Union called on both sides to exercise restraint and end the fighting.
Special correspondent Ahmed Aldabba in Gaza City contributed to this report.