UNITED NATIONS - On the anniversary of Israels deadly offensive against Gaza, UN Secretary-General Ban Ki-moon said on Sunday that issues that led to this conflict remained unresolved and Israeli blockade of borders was violation of Palestinians basic human rights. There is a sense of hopelessness in Gaza today for 1.5 million Palestinians, half of whom are under 18, the UN chief said in a statement marking the one-year anniversary of the Israeli bombing that killed 1,400 Palestinians and wounded thousands others. The quality and quantity of humanitarian supplies entering Gaza are insufficient. Broader economic and reconstruction activity is paralysed and the people of Gaza are denied basic human rights, he said. He also asked Palestinian outfit Hamas not to resort to violence and called on people of both countries to work out a solution to end the decades-old conflict. AFP adds: The UN chief said he feared that the underlying causes of Israels deadly war in the Hamas-run Gaza Strip have still not been addressed a year after the onslaught. A year after the start of 'Operation Cast Lead, the Secretary-General is deeply concerned that neither the issues that led to this conflict nor its worrying aftermath are being addressed, Ban said in a statement posted on the UN website on Sunday. Ban said a fundamentally different approach to Gaza was needed. The Secretary-General calls on Israel to end the unacceptable and counter-productive blockade of Gaza, facilitate economic activity and civilian reconstruction, and fully respect and uphold international law. He calls on Hamas to bring an end to violence and fully respect and uphold international law. The Secretary-General also calls on all Palestinians to work for unity and elections within the framework of the legitimate Palestinian Authority. Todays anniversary is a reminder of the bitter consequences of the continuing Israeli-Palestinian conflict, to which there is and can be no military solution. Meanwhile, Washington has questioned Israel over a deadly West Bank raid over the weekend that killed three members of Palestinian President Mahmud Abbas Fatah movement, an Israeli official said on Sunday. Washington has passed on the Palestinians concerns over why the raid was carried out without their forces being given an opportunity to arrest the men, the official told AFP on condition of anonymity. Israel said the three men shot dead in Nablus on Saturday were behind the killing of a settler in the occupied West Bank two days earlier who was ambushed on a road and had his car sprayed with bullets. But the military confirmed that none of the Palestinians fired any shots at the troops that came to arrest them at three different locations and said only one of them was armed. Family members of the three men said the troops entered without warning and killed all three in cold blood, insisting none had resisted arrest. One of the men was a member of the Al-Aqsa Martyrs Brigades, a group loosely linked with Abbas Fatah movement, and the other two were Fatah activists, Palestinian security officials said. A US official quoted by the left-leaning Haaretz daily also said on Sunday that Washington had contacted Uzi Arad, a senior aide to Prime Minister Benjamin Netanyahu, over the incident. We expressed our concern and encouraged both sides to continue their security cooperation, he was quoted as saying. We talked to both sides in order to get full information about what happened, he added.