(Updates with Israeli plans, rocket attack on crossing) By Peter Apps LONDON, June 25 (Reuters) - Unloaded from trucks and ferried across the no man's land between Israel and Gaza, aid is trickling into the Hamas-controlled strip but the main freight crossing is shut and relief workers say a crisis is looming. Even before Hamas Islamists took control in violent fighting with their secular Fatah counterparts earlier in the month, triggering the closure of front-line crossing points, aid agencies were warning of growing hardship for ordinary people. All sides, including Israel, say they are committed to getting essential aid to the 1.5 million Gaza residents. However, the cargo checkpoint at Karni remains shut for security reasons and the United Nations World Food Programme (WFP) says the remaining supply links are tenuous. "Put simply, the noose is tightening at the moment," WFP Gaza emergency coordinator Kirsty Campbell told Reuters. "There is not enough getting in. We hope by the end of the week there may be. But it is quite an ambitious task." Prices of essential foods had risen by between a half and a third, she said, with authorities in Gaza taking action to control the supply of flour and prevent traders from hoarding. Farmers are short of supplies and hospitals of medicines. Aid workers say an international boycott of the Hamas-led government prevented public sector workers from receiving their full salaries, deepening poverty in the strip. Donors have now relaxed the boycott on President Mahmoud Abbas's administration on the West Bank, but the United States and Israel say the embargo will remain in place on the Hamas administration in Gaza. That outrages some aid groups. Oxfam says the boycott has left essential water equipment waiting at the border for months and that, as a result, a key sewage works could overflow, swamping up to 10,000 people and contaminating water for 300,000. AVOIDABLE CRISIS "The international community is closing its eyes to its humanitarian obligations and allowing the suffering to intensify," said the director of Oxfam International, Jeremy Hobbs. "Aid is being drip fed across the border. We urge the key players to resolve what has been a completely avoidable crisis." Instead of reopening Karni, Israel says it will bring about 3,000 tonnes of emergency supplies into Gaza through the smaller Kerem Shalom and Sufa passages five days a week. Israel believes this will be enough to avert a humanitarian crisis. Still, some aid groups say the boycott may risk further radicalising Gaza residents but analysts believe there is little chance of international donors aiding Hamas. Abbas and Fatah are also keen to isolate Hamas further by withholding all but essential aid, some Western diplomats said. The WFP said it had managed to get about 650 tonnes of food into Gaza last week and hoped to push 11 truckloads through the Sufa crossing point on Monday. It is a slow process. A gate on the Israeli side is opened to allow pallets of food to be unloaded into no man's land by fork lift truck in the morning, then the gate on the Gaza side opens to allow the food to be put on trucks in the afternoon. A rocket attack by Gaza militants forced the closure of the Kerem Shalom crossing on Monday. The United Nations said the attack endangered "the provision of vital humanitarian assistance to the civilian population of Gaza".
