JERUSALEM  - Amnesty accused Israeli forces on Thursday of war crimes in Gaza, saying they used children as human shields and conducted wanton attacks on civilians, in a report rejected as "unbalanced" by Israel.

The London-based human rights group also accused Hamas of war crimes, but said it found no evidence to support Israeli claims that Gaza's Islamist rulers used civilians as human shields during Israel's massive 22-day offensive.

It reiterated its call for international arms embargoes against Israel and Hamas, and called for "criminal investigations in national courts" under universal jurisdiction wherever there is sufficient evidence of war crimes.

"Much of the destruction was wanton and resulted from direct attacks on civilian objects," Amnesty said in a report on the December-January war on the Gaza Strip.

In numerous cases, Israeli troops forced Palestinians to stay in one room of their home while turning the rest of the house into a base and sniper position, "effectively using the families, both adults and children, as human shields and putting them at risk," the group said.

"Intentionally using civilians to shield a military objective, often referred to as using 'human shields' is a war crime," Amnesty said.

One Palestinian was quoted as saying Israeli troops forced him to go into a house to check whether gunmen holed up inside were still alive. They were, and threatened to kill him if he returned. The soldiers later forced him to check on the fighters two more times.

The report said it found no evidence Palestinian fighters directed civilians to shield military objectives from attacks, forced them to stay in buildings used by militants or prevented them from leaving commandeered buildings.

But it said Palestinian armed groups fired hundreds of rockets into southern Israel which "constitute war crimes."

Amnesty also accused Hamas of endangering Palestinian civilians by firing rockets from residential areas and storing weapons and ammunition there.

More than 1,400 Palestinians and 13 Israelis died during the offensive Israel launched in response to rocket fire by militants in the impoverished and overcrowded territory.

Amnesty said 300 children were among those killed.

It said hundreds of civilians were killed with high-precision weapons. "Others, including women and children, were shot at short range when posing no threat to the lives of the Israeli soldiers," it said.

"Wilful killings of unarmed civilians are war crimes," Amnesty said.

It said Israel's use of white phosphorus shells was also a clear breach of international law.

White phosphorus is not illegal if used as a smokescreen in open areas "but it should not be used in a densely populated area as it was used here," said Donatella Rovera, who led an Amnesty mission to Gaza and southern Israel.

The Israeli military called the report "unbalanced" and "distorted."

"The slant of their report indicates that the organisation succumbed to the manipulations of the Hamas terror organisation," a statement said.

The military insisted its forces used "fighting methods and advanced technology to minimise harm to the civilian population while engaging terrorists who were operating from densely populated areas and using the local population as 'human shields'."

It also accused Amnesty of ignoring "the blatant violations of international law perpetrated by Hamas."

Hamas also sharply criticised the report.

"It falsely accuses Hamas while playing down the seriousness of the crimes committed by the Israeli occupation," Sami Abu Zuhri, a spokesman for the Islamist movement.

"It puts the executioner and the victim on the same footing," he said.