SANA, Yemen — A senior official here said Thursday that the young Nigerian man accused of trying to bring down an airliner approaching Detroit on Christmas Day had met with Qaeda operatives and probably with Anwar al-Awlaki, a radical American-born Internet preacher, in Yemen before setting out on his journey.
But the official, Rashad al-Alimi, the deputy prime minister for national security and defense, cited Yemeni investigations and said that the Nigerian, Umar Farouk Abdulmutallab, 23, had acquired the explosives used in the failed attack not in Yemen, which he left on Dec. 4, but in Nigeria, where he changed planes at the Lagos airport on Dec. 24, boarding a flight to Amsterdam and then Detroit.
Mr. Alimi’s remarks, made at a news conference in Sana, offered Yemen’s most definitive public reconstruction of Mr. Abdulmutallab’s movements before the attack. But the account differed in many respects from some those from British, Ghanaian and Nigerian officials, on crucial points: where he was recruited, where he obtained the explosives, even how long he spent in the Nigerian airport.
According to previous accounts, Mr. Abdulmutallab flew from Accra, Ghana, on Dec. 24, and had a layover at the airport in Lagos, Nigeria, on his way to board the Detroit-bound Northwest Airlines flight to Amsterdam. American officials have said that Mr. Abdulmutallab told F.B.I. investigators that Al Qaeda in Yemen had trained him and furnished him with the sophisticated bomb he concealed in his underwear.
Mr. Alimi denied emphatically that Mr. Abdulmutallab left Yemen with the explosives, saying the suspect obtained them in Nigeria, though he offered no specific evidence for his assertion.
The Yemeni official said, for instance, that Mr. Abdulmutallab was recruited in London; British officials have said that they knew he had met with extremists there, but that he was not seen as a threat.
It was unclear how Mr. Abdulmutallab would have acquired the explosives in Nigeria. Nigerian officials have said that he spent less than 30 minutes at the airport and went through the requisite security checks. . But the Lagos airport is also known for its corruption and chaos, and officials in Ghana dispute the Nigerian account, saying Mr. Abdulmutallab spent nearly four hours in Lagos before leaving. Analysts suggest that it would be logical for Mr. Abdulmutallab to travel through as few airports as possible with the explosives.
Investigators in many countries are seeking clarity on Mr. Abdulmutallab’s movements in the months and weeks before the attack.
The broad timeline offered by the Yemeni official meshes with previously established outlines of Mr. Abdulmutallab’s travels: he went to Sana to attend Arabic language classes in August 2009, was driven to the airport on Sept. 21 with an exit visa but then slipped out of sight.
Mr. Alimi said that, before the Nigerian left Yemen, on Dec. 4, he went to Shabwa Province, a remote, rugged area in central Yemen. There, he said, he met with “Al Qaeda elements” and probably with Mr. Awlaki.
Mr. Alimi said that the meeting was in a building bombed later, on Dec. 21, by Yemeni forces, while another Qaeda meeting was under way.
“This place is indeed associated with Anwar al-Awlaki,” Mr. Alimi said.
Mr. Alimi did not rule out that Mr. Abdulmutallab might have traveled through other remote areas of Yemen. He said British and American intelligence services had not warned the Yemeni authorities about any security concerns relating to him before the attack.
Mr. Awlaki’s calls for holy war resonate among Qaeda sympathizers. He exchanged e-mail messages with an American officer, Maj. Nidal Malik Hasan, who is accused of a shooting spree at Fort Hood, Texas, in which 13 people were killed last November.
Mr. Abdulmutallab flew into Ghana from Addis Ababa, the Ethiopian capital, on Dec. 9, according to Ghanaian officials. His further airline tickets were bought there, and paid for in cash.
Mr. Alimi’s news conference followed an announcement Wednesday that Yemen had arrested three militants from a cell of Al Qaeda suspected of making threats against Western targets here.
The three had been wounded on Monday in a fight with Yemeni forces in the Arhab region, 25 miles from Sana, the capital, and were captured at a hospital, officials said.
Mr. Alimi said Thursday, however, that Muhammad al-Hanq, a regional Qaeda leader who was the object of the security operation on Monday, had not so far been captured.
The arrests on Wednesday are a good sign of Yemen’s new focus on fighting the Qaeda affiliate, a senior Western diplomat said.
The government’s ability and willingness to grapple with terrorist suspects are major questions. Its reach is limited, and it is fighting rebels in the north and secessionists in the south that it regards as more direct threats to its power.