Friends react during the funeral of Palestinian child Lian Al Shaer, after she succumbed to her injuries sustained in last week's Israeli air strikes, in Khan Younis on Thursday. AFP

Last week saw three days of intense conflict between Israel and Islamic Jihad group in the densely populated Palestinian enclave of Gaza.

"Inflicting hurt on any child during the course of conflict is deeply disturbing," Michelle Bachelet, the United Nations High Commissioner for Human Rights, said in a statement.

"The killing and maiming of so many children this year is unconscionable." The Israeli air and artillery strikes targeted positions of Islamic Jihad group.

Her office said that 19 Palestinian children had been killed in the Palestinian territories in the recent unrest, taking the total number this year to 37.

Seventeen children were killed during the Gaza hostilities from Aug.5 to 7, while two more were killed on Tuesday in Israeli law enforcement operations in the West Bank.

The UN Human Rights Office OHCHR said that among the 48 Palestinians killed in last week's Gaza conflict, there were at least 22 civilians. They included the 17 children and four women.

Of the 360 Palestinians reported injured, nearly two-thirds were civilians, including 151 children, 58 women and 19 older people, OHCHR said.

"In a number of incidents, children were the majority of casualties," Bachelet's office said.

"Launching an attack which may be expected to incidentally kill or injure civilians, or damage civilian objects, in disproportionate manner to the concrete and direct military advantage anticipated, is prohibited," she said. "Such attacks must stop."

Bachelet called for investigations into all incidents where any person was killed or injured. "An almost total lack of accountability persists in the occupied Palestinian territory," she said.

"Whether for violations of international humanitarian law by all parties in hostilities in Gaza, or for recurring Israeli violations of international human rights law and the law of occupation in the West Bank, including East Jerusalem."

Agence France-Presse