The Gaza shooting gallery

Palestinians carry the body of one of four children of the Abu Meatak family during their funeral in Beit Lahiya, northern Gaza Strip, Monday, April 28, 2008. An Israeli tank shell fired during a clash with Palestinian gunmen tore into a tiny Gaza Strip home on Monday, Palestinian officials said, killing a Palestinian woman and four of her children and threatening efforts to arrange a truce between the warring side.(AP Photo/ Hatem Moussa)

While Egypt tries to broker a cease fire between Israel and Palestinian militants, the low-intensity war in Gaza continues to take its toll.

The latest innocent victims were a mother and four of her children who lived in the drab Gaza town on the front-lines of the repeated Israeli-Palestinian clashes.

The five were killed on Monday when the Israeli military fired on suspected militants.

Palestinians say the five were killed when Israeli artillery shrapnel hit their home as the family was sitting down for breakfast. The Israeli military says the five were killed by a secondary explosion when the Israeli army hit two militants carrying bags filled with explosives.

According to the report below from an Al Jazeera reporter on-the-scene, there was no secondary explosion caused by the bag. The five, according to this report, were instead killed by a second Israeli strike that was targeting an unarmed militant who was trying to escape.

The Israeli military and Defense Minister Ehud Barak offered no apologies for the deaths and put the blame on Hamas, the hard-line movement controlling Gaza.

"The State of Israel and the IDF place complete and utter responsibility on the Hamas terrorist organization for the injury and killing of uninvolved civilians," the Israeli military said in a statement. "By intentionally operating from within heavily populated areas, and using them for cover, the terrorist organization exploits civilians as human shields."

The claim failed to assuage many people, so the Israeli military announced that it was launching an internal investigation and planned to get answers within 48 hours.

The grim images are all-too-familiar: From Qana, Lebanon during the 2006 war with Hezbollah to the killing of eight Palestinians on a beach picnic in 2006 to the killing of 18 Palestinians hit by Israeli artillery in 2006 to the recent killing of Reuters cameraman Fadel Shana by an Israeli tank shell, time and again, Israel has been forced to defend its questionable military actions.

Today, Israeli Prime Minister Ehud Olmert expressed "deep remorse" for the latest deaths, but then blamed Hamas for turning Gaza into an "inseparable part of the war."

While Israel tries to put the blame on Hamas, that does not relinquish it of its battlefield responsibilities in Gaza.

Under established rules of conflict, Israel must do all it can to avoid unnecessary deaths when fighting Gaza militants. And it has to consider whether an attack will create unreasonable civilian deaths.

The issue was described well during the 2006 Israel-Hezbollah war in this Human Rights Watch fact sheet.

Every time this issue arises, it inevitably gets muddled in a debate over what is reasonable on the battlefield. There are no hard-and-fast rules that set out how many innocent civilians it is OK to kill in battle.

But that debate misses the larger conundrum for Israel.

When I wrote about this during Israel's 2006 war against Hezbollah, a variety of analysts said such strikes only served to undermine Israel's image and create more resentment.

At this point, the Israeli military is investigating two contentious attacks in Gaza (Monday's attack and the killing of Fadel Shana) that have generated international outrage just as Israelis are preparing to celebrate their 60th anniversary.

We'll soon see how Israel responds to the latest challenges.