Children in the Gaza Strip continued to suffer and feel insecure despite a ceasefire that has mostly ended three weeks of intense fighting between Israel and Hamas, the UN special envoy for children and armed conflict said Monday.

Radihika Coomaraswamy said grave violations of child rights had been committed during the fighting that began on December 27 when Israel Defense Forces launched airstrikes against Hamas militants who had been firing rockets and mortars into southern Israel.

She said those violations included killing and maiming, and denial of humanitarian access. Fifty-six per cent of Gazans are children under 18.

"During the recent hostilities, there were no safe space for children and the crossings out of Gaza were, and remain, virtually sealed," she said.

The fighting killed more than 1,300 people in Gaza, one-third of them children and women. Thousands of people were injured.

Turning to children in Israel, Coomaraswamy said: "There is no doubt that children live in constant fear of missile attacks in southern Israel. The need for psycho-social support has increased recently."

Coomaraswamy, who recently visited Ashkelon in southern Israel, said the indiscriminate firing of rockets by Hamas against Israel clearly violated international humanitarian law and should not be ignored simply because it was less severe than the Israeli airstrikes against Gaza.

She said children in both Gaza and Israel have expressed "anger and despair as a manifestation of their desire for accountability."

She supported an international investigation into the killing.

The UN Development Programme (UNDP) released Monday a telephone survey of 1,815 households in Gaza, those that still have landline phones, showing that 75 per cent of those surveyed expressed insecurity because of the Israeli-Palestinian conflict and border closing.

The survey said 45 per cent of households that still have a telephone reported war-inflicted damage to their homes, ranging from artillery shells to shattered windows.

Two-thirds of households polled said they needed assistance, identifying emotional and psychological aid as a top priority (28 per cent), followed by unemployment (16 per cent) and financial support (14 per cent).

The survey said half of respondents considered emotional and psychological aid as a priority for children because of their signs of stress such as bedwetting, nightmares, aggressive behaviour and anxiety.