Over the last four weeks the world has looked on in horror as women, men and children have borne the brunt of the conflict in the Gaza Strip and Southern Israel. It is not just the number of casualties that has sent shockwaves, but the high proportion - around half – who are civilians.

Their deaths and injuries are not the inevitable consequences of war, and can not be discounted as 'collateral damage'. These casualties represent mounting evidence of war crimes, committed on both sides of the conflict.

A ceasefire has been declared. Now it is imperative the United Nations and international community fully investigate these crimes and hold the perpetrators to account.

International law prohibits attacks on civilians and civilian objects, as well as attacks that are disproportionate and/or indiscriminate and which endanger civilians.

Yet, for eight years, both sides in the conflict have been guilty of targeting or endangering civilians. Since September 2000, Palestinian groups have killed some 1,100 Israelis and Israeli forces have killed some 5,500 Palestinians.

Israeli forces have bombed civilian homes and other buildings, arguing that they had been used as cover by gunmen firing at Israeli targets. However, Israeli forces know that Palestinian fighters usually vacate the areas as soon as they have fired, and that any reprisal attacks will in most cases cause harm to civilians, not gunmen.

In further contravention of international law, during the recent conflict Israel continued its blockade of Gaza, denying access to humanitarian and medical assistance. On the Palestinian side, Amnesty International has for years condemned and campaigned against human rights abuses committed by armed groups, including suicide bombing and rocket attacks.

Both Israeli soldiers and Palestinian gunmen have fired at each other from areas close to civilian homes, endangering their inhabitants. Further, Israeli soldiers and Palestinian fighters have used Palestinian civilians as human shields, a practice prohibited under the Geneva conventions.

In the past, Israeli soldiers have frequently taken over Palestinian homes, effectively imprisoning their occupants, to use as military observation and firing positions. In other cases, they have forced Palestinian civilians, at gunpoint, to go before them into buildings from which they feared attack.

These practices must be the subject of an urgent and thorough independent and impartial investigation by the United Nations. The UN should insist on full accountability for war crimes and other serious violations committed during this conflict. Alleged violations must be thoroughly and impartially investigated, and any persons found responsible brought to justice in fair trials.

In the meantime, the UN Security Council must assist the success of a ceasefire by imposing an immediate, comprehensive arms embargo on all parties to the conflict in Gaza to prevent any further flow of arms to the region.

Those who provide weapons and other military equipment or assistance to the parties involved in this conflict are not living up to their responsibility to ensure that the equipment is not used to violate human rights.

A Security Council arms embargo will not only help to prevent new weapons supplies reaching the two sides, but will also send a powerful signal to Israel and Hamas about the Council’s determination to uphold international law. On both sides of the conflict, perpetrators of war crimes must be brought to justice.

To join Amnesty International in calling for full accountability for the Gaza violence visit www.amnesty.org.au