Seized al-Qaeda member could be American

ISLAMABAD, PAKISTAN -- A member of al-Qaeda who might be an American has been arrested by Pakistani authorities near the metropolis of Karachi, two Pakistani intelligence officers said Sunday.

The man's identity could not be confirmed Sunday night. One Pakistani intelligence official said he is Adam Gadahn, a California native and the first U.S. citizen to be charged with treason in 52 years, but an informed source in Washington cautioned that the report of Gadahn's capture appeared to be "bogus."

U.S. officials said they could not confirm Gadahn's detention, and it was unclear early Monday whether he is the person Pakistani authorities said had been captured.

One military intelligence official in Karachi said a man named Abu Yahya had been arrested; Gadahn is also known by the aliases Abu Yahiya Gadahn, Yahya Majadin Adams and "Azzam the American." But a senior security official told Agence France-Presse that a different militant -- one named Abu Yahiya -- is the captive.

Gadahn, a convert to Islam who migrated to Pakistan 12 years ago, appeared in an al-Qaeda video released Sunday, exhorting Muslims to stage attacks within the United States.

Reports of the arrest, which surfaced in Pakistani news media Sunday, followed a string of top-level militant captures and killings by Pakistan. Authorities have nabbed several members of the Afghan Taliban's leadership, including its No. 2 commander, in recent weeks, as well as al-Qaeda operatives. On Friday, a deputy leader of Pakistan's Taliban was killed in a Pakistani airstrike, the government said.

Several of the fighters have been arrested in Karachi, a teeming city that is far from the militant sanctuaries along the Afghanistan-Pakistan border but has become a financial and logistical hub for terrorist organizations.

Khan is a special correspondent. Staff writer R. Jeffrey Smith in Washington contributed to this report.