DHAKA: An airstrike hits an open air market. An explosion rocks a school-turned-shelter. A booby-trapped tunnel explodes.

These were among the scenes in Gaza in a more-than-three-week-old conflict that has left more than 1,300 people dead and even more wounded.

The violence between Israel's military and Palestinian militants played out Wednesday against a backdrop of another failed humanitarian cease-fire attempt, with militants firing rockets from Gaza into Israel and Israelis responding with airstrikes.

With more than 100 people, mostly civilians, reportedly killed Wednesday in the fighting, the United Nations and the United States demanded more be done to protect civilians.

A large part of the criticism has been leveled at Israel and its airstrikes, which have bombarded Gaza. Israel in turn has accused Hamas of hiding weapons, including rockets, in schools and launching attacks from near shelters.

More than 1,300 Palestinians have been killed since the conflict between Israel and Hamas began on July 8, the Palestinian Ministry of Health in Gaza said.

The number of militants killed is unclear, but the United Nations estimates that 70% to 80% of the dead are civilians.

Three more Israeli soldiers were killed Wednesday, bringing the total to 56 dead. Three civilians also have been killed in Israel.

While saying Israel has a right to defend itself, White House Deputy Press Secretary Eric Schultz said, "We've also been very clear that Israel needs to do more to live up to its own standards to limit civilian casualties."

It was a sentiment echoed by U.S. State Department spokeswoman Marie Harf, who also said Israel is being put in a tough situation because "Hamas is hiding rockets in places to prevent the Israelis from going after them."

"So look, Hamas is taking steps here that put civilians at risk. But we do believe the Israelis need to do more," Harf told reporters during a briefing, reports CNN.

While there were calls on Israel to do more to protect civilians, the United States also agreed to Israel's request to resupply it with several types of ammunition, a U.S. defense official told CNN on condition of anonymity. It's not an emergency sale, the official said.

Among the items being bought are 120mm mortar rounds and 40mm ammunition for grenade launchers, the official said. Those will come from a stockpile the United States keeps in Israel, which is worth more than $1 billion.

BDST: 0923 HRS, JUL 31, 2014