ISLAMABAD (Reuters) - Dismal conditions in flood-hit areas in southwest Pakistan could force thousands of Pakistanis and Afghan refugees to cross the border into Iran, the UN refugee agency warned Thursday. Balochistan province was the first to be hit by the countrys worst floods, initially displaced some 200,000 people. But the region has been largely ignored after more menacing waters raged in other parts of the country. The number of displaced people there is close to one million, and lack of assistance could make them head to neighbouring Iran, said Mengesha Kebede, the UN High Commissioner for Refugees (UNHCR) representative in Pakistan. This has not happened yet ... but definitely everybody is aware of significant movement that is taking place, Kebede said, adding contingency plans there were underway. If we do not meet the humanitarian needs of the people, not only will there be social discontent but they will move for other fields, and unfortunately what that means is they could even go into Iran, he told a news conference. The calamity has displaced more 400,000 people inside Balochistan. Another 600,000 have joined them from the neighbouring Sindh province. I have worked in humanitarian situations globally ... to be honest with you, I have not seen such a disgusting situation, as I saw in Balochistan, said Kebede. Two schools sites I visited, I literally couldnt walk in, fundamentally because the entire school has one toilet which is being used by people ... and basically people are defecating all over the place. Kebede called for scaled up relief activity in Balochistan to prevent a major humanitarian disaster there. I feel it would be tragic if because of the lack of assistance, Pakistanis, Afghan refugees were to cross the border, seeking help and assistance in Iran, he said. We need to ensure that Balochistan is not forgotten.