OSLO/KABUL (Reuters/AFP) - The United States is the biggest obstacle to coordinating aid efforts in Afghanistan, UN special envoy Kai Eide was quoted as saying on Wednesday. Resistance to change and a lack of cooperation between aid organisations are hampering Afghanistans development, the Norwegian told the Dagsavisen newspaper in his home country. The Americans are the biggest problem, using enormous resources, particularly through the PRTs (Provincial Reconstruction Teams) and through contractors, said Eide, who is responsible for coordinating international civilian efforts in Afghanistan. Eide said that even though there was an agreement to coordinate international efforts and help develop Afghan institutions, most countries have continued to work separately. I see signs of improvement, but there are still significant aid resources - many hundreds of millions of dollars - that we do not have any control over, Eide said. There is an amazing resistance to change, he said. We are moving very slowly. Eide applauded US President Barack Obamas Afghan strategy, announced in March, for putting more emphasis on building civilian institutions. But he warned against an Americanisation of international efforts in Afghanistan. Let us not make this too much into an American engagement, Eide said. The formulation of policies must happen in close cooperation between the Americans and the Europeans. But that will demand that the Americans listen. Meanwhile, airstrikes, gunbattles and attacks killed 28 people across Afghanistan on Wednesday, including a government official shot dead with three of his sons near the Pakistani border, officials said. In the latest bloodshed, blamed on Taliban who recently vowed to step up attacks against the Western-backed government, a district governor and his grown-up sons were ambushed and killed in the east, the Interior Ministry said. Mohammad Nader, Governor of the Omna district in the eastern province of Paktika, was travelling with his family to go back home near the Pakistan border when armed insurgents attacked, the Ministry said. The Interior Ministry and local government in Paktika blamed the attack on the Taliban, who have strongholds in the province along the porous border with Pakistan, where militants have carved out safe havens in the mountains. Elsewhere in Paktia, Afghan security forces backed by Nato troops and air power killed at least 15 insurgents in the early hours, the alliance said. The insurgents were killed in airstrikes and gunbattles after attacking the combined troops during a security patrol, the statement said. Further north, a rocket slammed into a wheat field in the eastern province of Kunar, which also lies on the Pakistani border, killing a beggar, provincial officials told AFP. An Afghan border policeman and three insurgents were killed Wednesday in an exchange of fire initiated by the Taliban attackers in eastern province of Nangarhar, said Mohammad Zaman Mamozai, the local border police chief. In the centre of the country, the Afghan and US militaries said they killed four Al-Qaeda-linked militants and detained 10 others during operations against extremist Islamists in Logar province. The suspects were killed when troops looking for members of the radical Haqqani network raided compounds south of the capital Kabul, they said. The network, part of the Taliban, was established by Afghan Soviet resistance commander Jalaluddin Haqqani but is now believed to be led by his sons, notably Siraj Haqqani, and has carried out attacks in Kabul. Five men were detained during the operation, on suspicion of being involved in roadside bombs and suicide attacks on troops, the statement said. In another incident, the Nato military force said Taliban fired seven mortar rounds near a town in northeastern Afghanistan and killed seven civilians, the NATO military force said. Eight more civilians were wounded in the attack near the town of Asadabad, the provincial capital of the mountainous province of Kunar on the border with Pakistan, it said in a statement.