Kabul , Afghanistan ( CNN ) -- A car bomb exploded in a busy market in eastern Afghanistan Tuesday , killing more than 40 people , officials said , in what is said to be the single worst attack in the country this year . Afghan Deputy Interior Minister Mohammad Ayoub Salang said 42 people were killed and more than 30 others were wounded in the attack in the Urgon district of Paktika province . The United Nations Assistance Mission in Afghanistan had different figures , stating that at least 43 civilians , including eight children , were killed , and 67 were wounded . The car was driven by a suicide bomber who detonated explosives after police ordered him to stop his car , said Nissar Ahmad Abdulrahimzai , deputy police chief of Paktika province . Abdulrahimzai said he feared the death toll would rise and there is at least one government official reporting more deaths . The United Nations , which calls the assault a suicide attack , says it 's the single deadliest strike this year in the country . `` Today 's appalling attack during Ramadan -- an occasion that should observed in a spirit of peace and compassion -- should be condemned in the strongest possible terms and the perpetrators must be held accountable , '' UNAMA head Jan Kubis said . The Taliban denied involvement . Another attack in Kabul . Meanwhile , in the capital , Kabul , the Taliban claimed responsibility for an attack early Tuesday on a vehicle used by presidential palace employees . Taliban spokesman Zabihullah Mujahid said in a statement to media that three people were killed and six others injured in the explosion . Hashmatullah Stanekzai , a spokesman for the Kabul police chief , earlier told CNN that at least two people were killed and five injured . He said all the victims were working in the presidential palace media department . Security remains a major concern in Afghanistan , from which the United States is due to withdraw most of its troops by year 's end . The latest violence comes amid disputes over the country 's recent presidential election . During a visit to Kabul on Saturday , U.S. Secretary of State John Kerry announced that an audit of votes would be carried out to decide the outcome of the election . Both candidates , Abdullah Abdullah and Ashraf Ghani , have alleged large-scale vote fraud and manipulation during the runoff last month .
NEW : 42 killed in Afghanistan market attack . NEW : The Abdulrahimzai says it 's the single worst attack Tuesday in Paktika . The device was detonated by a suicide bomber , a police official says . Afghanistan continues to face major security challenges .