KABUL, Afghanistan — The Taliban have offered to exchange the body of a US Navy sailor they said was killed in an ambush two days ago in exchange for insurgent prisoners, an Afghan official said Sunday.US and NATO officials confirmed that two American Navy personnel went missing Friday in the eastern province of Logar, after an armored sports utility vehicle was seen driving into a Taliban-held area.RELATED:Al-Qaida group: We captured US troopsIn a telephone interview Sunday with The Associated Press, Taliban spokesman Zabiullah Mujahid said the pair drove into an area under insurgent control, prompting a brief gunfight in which one American was killed and the other was captured. He said both were taken to a "safe area" and "are in the hands of the Taliban."Mujahid made no mention of any offer to exchange the pair for Taliban prisoners. A local Afghan officials said the Taliban sent a message through intermediaries offering to hand over the body in exchange for jailed insurgents.Abdul Wali, the deputy head of the provincial governing council, said local authorities responded by saying, "Let's talk about the one that is still alive." The insurgents said they would have to talk to superiors before making any deal.Hundreds of posters of the two missing sailors have been hung at checkpoints throughout the Logar province where NATO troops are stopping vehicles, searching people, peering inside windows and searching trunks. The posters, with photographs of the missing sailors, state: "This American troop is missing. He was last seen in a white Land Cruiser vehicle. If you have any information about this soldier, kindly contact the Logar Joint Coordination Center," run by coalition and Afghan forces. A phone number is listed along with information about a $20,000 reward being offered for information leading to their location.The photographs show one clean-shaven sailor wearing a soft cap and another with short-cropped hair, wearing a blue civilian shirt and a white undershirt."Last night coalition helicopters were flying patrols," said Din Mohammed Darwesh, spokesman for the provincial governor of Logar. "Our latest, accurate information reports are that they are still in the area."He said the governor's office was upset because the two Americans left their base without notifying Afghan security forces in Logar."Normally, when Americans are leaving, they inform our security forces. This was an abnormal situation," Darwesh said.NATO officials have offered no clear explanation why the sailors were in Logar. The two left their compound in the Afghan capital, Kabul, Friday afternoon but never returned, NATO said in a statement.The visiting chairman of the US Joint Chiefs of Staff, Adm. Mike Mullen, told reporters Sunday that he didn't have all the details, but "from what I know right now, this is an unusual circumstance." He would not elaborate.Earlier Sunday, Mujahid, the Taliban spokesman, told the AP that he had no information about US sailors in Taliban hands. He said he would look into the reports. He claimed responsibility in a subsequent conversation. That suggested that the Friday attack was a spur-of-the-moment move and that the militants are trying to figure out what to do about it.A NATO official, speaking on condition of anonymity because of the sensitivity of the event, confirmed the two were Navy personnel, but would not identify their unit to avoid jeopardizing search operations.Samer Gul, the chief of Logar's Charkh district, said a four-wheel drive armored sports utility vehicle was seen Friday night by a guard working for the district chief's office. The guard tried to flag down the vehicle, carrying a driver and a passenger, but it kept going, Gul said."They stopped in the main bazaar of Charkh district. The Taliban saw them in the bazaar," Gul said. "They didn't touch them in the bazaar, but notified other Taliban that a four-wheel vehicle was coming their way."The second group of Taliban tried to stop the vehicle, but when it didn't, insurgents opened fire and the occupants in the vehicle shot back, he said.Gul said there is a well-paved road that leads into the Taliban area and suggested the Americans may have mistaken that for the main highway — which is much older and more dilapidated.The only US service member known to be in Taliban captivity is Spc. Bowe Bergdahl of Hailey, Idaho, who disappeared June 30, 2009, in Paktika province. That area is heavily infiltrated by the Hakkani network, which has deep links to al-Qaida. He has since appeared on videos posted on Taliban websites confirming his captivity.New York Times reporter David Rohde was also kidnapped in Logar province while trying to make contact with a Taliban commander. He and an Afghan colleague escaped in June 2009 after seven months in captivity, most of it spent in Taliban sanctuaries in Pakistan.Also, Saturday night in Logar, Afghan and coalition security forces detained two suspected insurgents in a clearing operation, NATO said Sunday. It was unclear whether the operation was directly tied to the search for the two missing sailors.In the northeast, meanwhile, insurgents recaptured a remote district of Nuristan province that has bounced between government and Taliban control in recent months.Afghan police retreated from Barg-e-Matal before dawn Sunday after days of heavy fighting in which at least five officers were killed, said Interior Ministry spokesman Zemeri Bashary."The pressure of the attack was heavy on them," Bashary said. He said they pulled back in order to prevent further casualties and were planning a counteroffensive from an area close to the district.