Q: How did the current conflict in Gaza begin?

A: Israel blamed the militant Islamist group Hamas for the kidnapping and killing in June of three Israeli teenagers in the West Bank, though Hamas did not claim responsibility. That led to an Israeli crackdown there on the group. In response, militants in the Gaza Strip fired rockets at Israel, which escalated its airstrikes on militant targets. After six Hamas militants were killed in an explosion in a tunnel last Monday, the group fired a heavy barrage of rockets at Israel, which responded with the current offensive.

Q: What are Israel's aims?

A: Prime Minister Benjamin Netanyahu has said that the aim of campaign is to strike a heavy blow against Hamas and compel it to stop the rocket fire at Israel. He is considering a ground push into Gaza, although he is said to be wary of getting Israeli troops bogged down in a costly ground war.

Q: What does Hamas want?

A: Hamas leaders have set conditions for a cease-fire, saying they want a lifting of Israeli and Egyptian border restrictions imposed on Gaza, the opening of the Rafah border crossing with Egypt and the freeing of prisoners rearrested by Israel in its West Bank crackdown in June.

Q: What is the reason for the lopsided casualty figures?

A: The Israeli military says it has dropped more than 2,000 tons of munitions on targets in the Gaza Strip, a densely populated area where residents have no bomb shelters or early warning systems alerting them to take cover. In Israel, air-raid sirens alert people to take cover in shelters and reinforced safe-rooms, and Israel's Iron Dome missile defense system has intercepted many incoming rockets.

Q: Are homes in Gaza a legitimate target?

A: Human rights groups say targeting residential houses is a violation of international law. The Israeli military says the buildings were used by militants to direct their operations, and are therefore legitimate military targets, and that in some instances warnings are given to occupants.

Q: How far have the rockets from Gaza reached into Israel?

A: Some have landed in areas south of the northern port city of Haifa, about 80 miles north of Gaza. Others have reached Tel Aviv and areas around Jerusalem.

Q: Why does the fighting continue?

A: So far there has been no effective mediator to broker a cease-fire between Israel and Hamas. The United States has offered to broker a truce, but it has no contact with Hamas, which it considers a terrorist organization. Secretary of State John Kerry has communicated with Egypt, Qatar and other regional players to help mediate an end to the fighting, so far without success. Netanyahu has pledged to continue the offensive until rocket fire on Israel halts. Hamas says it will not agree to a truce unless its conditions are met.

Q: What's the international reaction?

A: President Obama has said Israel has the right to defend itself against rocket attacks, but he has cautioned against further escalation. The United States has offered to broker a new cease-fire agreement based on one in 2012. The United Nations Security Council has called for an immediate truce.

McClatchy News Service