Two men on a motorbike gunned down an Afghan provincial official as he walked to work Wednesday in the main southern city of Kandahar, police said. The assassination happened as Afghan human rights also reported Wednesday that 28 civilians have been killed so far in NATO's offensive on the Taliban stronghold of of Marjah, and urged pro-government forces to take greater care in distinguishing between civilians and militants. Taliban insurgents claimed responsibility for the provincial official's assassination. The killing comes as NATO and Afghan forces move into the 12th day of a major offensive to push militants out of a Taliban stronghold in neighboring Helmand province. The military alliance reported Wednesday that fighting was tapering off but bombs and gunmen continued to pose a threat. Clearing roadside bombs and precautions to prevent civilian casualties have slowed the largest joint military operation since the ouster of the Taliban regime in 2001, which planners see as key to taking on the insurgents in their southern heartland and turning around the war. But military officials say that despite the care taken, the offensive has still been marred by civilian deaths, including a rocket attack last week that hit a house and killed 12 people. The Afghanistan Independent Human Rights Commission said in a statement Wednesday that it had confirmed 28 civilians deaths in the Marjah fighting, based on witness reports. Thirteen children were among the dead. About 70 civilians have been wounded, 30 of them children, the commission said.NATO has confirmed at least 16 civilian deaths, while outside observers have reported 19. Military officials have said the assault in Marjah is just the first push in a campaign that will move east into Kandahar province – the Taliban's birthplace and where the hardline militant group still controls large swaths of territory. Underscoring the threat militants pose, attackers shot and killed Abdul Majid Babai, the head of Kandahar's information and culture department, in the provincial capital then drove off, said Mohammad Shah Farooqi, the deputy provincial police chief. Taliban spokesman Qari Yousef said the insurgents were behind the killing. Row over poll wacthdog Afghanistan's main opposition Wednesday criticized President Hamid Karzai's removal of foreign observers from a UN-backed electoral watchdog as “autocratic” and urged international pressure to ensure impartial elections. The five-member Electoral Complaints Commission (ECC), tasked with reviewing voting fraud, previously had three foreign members appointed by the United Nations, and last year nullified a third of Karzai's votes in the presidential poll as fraudulent. – AGnecies Karzai's decree to change the law could raise doubts over the panel's independence and set off new political tensions as NATO presses ahead with a major offensive against the Taliban. It could also put him in a new conflict with Western donors who have said they will not fund Sept. 18 parliamentary elections without electoral reforms. The main opposition National Front urged donor nations, legislators and other political parties to develop a mechanism to guarantee transparent elections. “This shows that Mr. Karzai is using one of his autocratic methods by not consulting with parliament, civil society and political parties,” National Front spokesman Fazel Sangcharaki said.