Unidentified kidnappers have abducted 11 Afghans working in a U.N.-affiliated landmine clearing program in the east of the country, officials said Saturday. The 11 were taken Thursday in a remote part of Nangarhar province, said Hazrat Hussain Mashreqiwal, provincial police spokesman. He did not name the abductors but said local officials and tribal elders were trying to negotiate the mine clearers' freedom. According to the United Nations there are an estimated 10 million mines scattered throughout 150 of Afghanistan's 400 districts, a legacy of 30 years of war. Children and farmers face the most serious threats from the discarded explosive devices. On Friday three children in central Ghazni province were killed when they tried to dismantle an old bomb. Also Saturday, a bomb killed an intelligence officer at his home in a remote northeastern corner of the country, officials were quoted as saying by the Associated Press. Mohammed Zahir, spokesman for Nuristan's governor, said the province's deputy intelligence chief Faiz Mohammed was the only casualty. It wasn't immediately known how the bomb was detonated.