The Israeli military came close to acknowledging for the first time yesterday its use of white phosphorus munitions during the war in Gaza, but continued to insist that it did not breach international law.

As fresh evidence emerged of Gazan civilians being burned by phosphorus, Avital Leibovich, the army spokeswoman, said its use was “legal according to international law...All the munitions we were using were legal, like the French, American and British armies. We used munitions according to international law.

“They [Hamas] were committing war crimes by putting the civilians in the front line,” she said. “If Hamas chooses to locate training camps, command centres...in the middle of the [civilian population]...look how populated it is...naturally they are endangering the lives of civilians. Hamas is accountable for the loss of the civilians.”

Major-General Amir Eshel, the army's head of strategic planning, said that firing shells to provide a smoke screen was legal. “It is the most nonlethal kind of weapon we used. I don't see any issue with that,” he said.

The Israeli newspaper Ma'ariv reported that the Israel Defence Forces (IDF) had privately admitted using phosphorus bombs, and that the Judge Advocate General's Office and Southern Command were investigating.

The Times first accused Israeli forces of using white phosphorus on January 5, but the IDF has denied the charge repeatedly. Phosphorus bombs can be used to create smoke screens, but their use as weapons of war in civilian areas is banned by the Geneva Conventions.

Yesterday reports emerged from Gaza about the killing of five members of the Halima family, when a single white phosphorus shell dropped on their house in the town of Atatra on January 3. Two others were in a coma and three were seriously wounded, according to doctors and survivors.

Salima Halima, 44, who is in Gaza City's Shifa hospital, said that the chemical burst in all directions after hitting her living room.

Nafiz Abu Shahbah, a doctor who trained in Britain and America, said he was sure white phosphorus was responsible. Her wounds at first appeared superficial “but it eats at the flesh, it digs deeper and gets to the bone...The whole body becomes toxic,” he said.

In the Jabaliya refugee camp, the Associated Press found a crater that was still producing acrid smoke days after the war ended, and in the town of Beit Lahiya a lump of white phosphorus burst into flames after some boys dug it up from beneath some sand.

Ban Ki Moon, the UN Secretary-General, expressed outrage at Israel's destruction of Gaza yesterday, when he became the first world leader to visit the Palestinian territory since the end of the war. “This is shocking and alarming,” he declared while visiting a UN warehouse that was still smouldering after being hit on Thursday, allegedly by white phosphorus shells. “I'm just appalled.”

Visibly angry, he condemned Israel's “excessive” use of force, and demanded that those responsible for shelling schools and other facilities run by the UN Relief and Works Agency during the 22-day offensive should be held to account. “It is an outrageous and totally unacceptable attack on the United Nations,” he said.

Israel has apologised for attacks on UN facilities but insisted in almost every case that Hamas fighters were using the buildings for cover.

Times Recommends

• Please help: maimed children of war want their lives back
• Cabal seizes diamond riches to buy power
• White House gatecrashers got to the president