Some 2.5 million Syrians need humanitarian aid, UN emergency aid chief Valerie Amos said Thursday in Damascus, raising the previous estimate by 500,000. \"The humanitarian situation has worsened since I was here in March,\" she said on the final day of her three-day visit to Syria. There was a growing need for health care, shelter, food, water and sanitation, she added. She said that bureaucratic restrictions, the ongoing violence and a lack of international funding was preventing the UN from delivering more aid.