Kabul , Afghanistan ( CNN ) -- The Taliban claimed responsibility for a suicide car bomb attack Sunday that targeted a NATO convoy in northern Afghanistan 's Kunduz province , killing at least three people and wounding 11 , a spokesman for the provincial governor 's office said . The attack came a day after Afghan President Hamid Karzai said the United States was involved in peace talks with the Taliban . U.S. officials have downplayed Karzai 's statements , saying there had been contact but no discussions substantial enough to be considered negotiations . `` I would say that these contacts are very preliminary at this point , '' Defense Secretary Robert Gates said in an interview broadcast Sunday on CNN 's `` State of the Union . '' The State Department is carrying out the contacts with the Taliban , which have been going on for `` a few weeks , maybe , '' Gates said . He added that the Taliban must come under further military pressure from the U.S.-led international military force and Afghan government forces before any substantive talks will occur . `` My own view is that real reconciliation talks are not likely to be able to make any substantive headway until at least this winter , '' Gates said in the interview conducted on Saturday . `` I think that the Taliban have to feel themselves under military pressure , and begin to believe that they ca n't win before they 're willing to have a serious conversation . '' News of the talks has done little to stem attacks in Afghanistan . On Sunday , a suicide bomber detonated a car full of explosives just as a convoy driven by German soldiers passed , said the governor 's spokesman , Mahbobellah Saidi . The convoy was attacked on the road leading to the airport in Kunduz City , the provincial capital , the Ministry of Interior said in a written statement . Two German soldiers sustained minor injuries , according to the German military . The target of the attack was unclear . Two armored vehicles were damaged and are in the process of being recovered , a military spokesman said . It was not immediately clear whether there were NATO casualties , though one of the convoy vehicles was damaged , Saidi said . But the Taliban claimed to have killed many soldiers in the attack . `` The troops were targeted accurately , according to the plan , and many of the soldier have been killed as a result of the attack , '' Taliban spokesman Zabiullah Mojahed told CNN by telephone from an unknown location . CNN can not independently verify the Taliban claim nor Saidi 's account . On Saturday , four NATO service members were killed in combat-related incidents in eastern and southern Afghanistan , and another four were killed in a vehicle accident in southern Afghanistan , NATO said . ISAF has not released the names of those killed , saying its policy is to defer casualty identification procedures to national authorities . CNN 's Stefan Simons contributed to this report .
Gates says U.S. contacts with the Taliban are preliminary . The Taliban says it targeted German troops in a suicide car bombing . Officials : Those confirmed killed or wounded are civilians . The attack comes after the Afghan president said the U.S. is in peace talks with the Taliban .