WASHINGTON — Abu Obeida al-Masri, an Egyptian al-Qaida chief responsible for attacks on U.S. forces in Afghanistan and linked to international terrorist plots, is dead, a U.S. counterterrorism official said Wednesday.

Al-Masri died of either hepatitis or a blood disease, in late 2007 in Pakistan's lawless tribal area bordering Afghanistan, a second counterterrorism official said. They spoke on condition of anonymity because of the sensitivity of the matter.

The official said al-Masri was "a senior external operations planner" for al-Qaida. He said he has been linked to the 2006 plot to blow up multiple airliners with liquid explosives traveling between the United Kingdom and the United States and Canada. He has also been linked to the July 7, 2005 bombings in London.

In Pakistan, army spokesman Maj. Gen. Athar Abbas said he had no information about the death of al-Masri. Several Pakistani intelligence officials contacted by The Associated Press had no immediate comment.

Based in the mountainous Afghan province of Kunar, al-Masri was believed to have been in charge of planning attacks on U.S.-led coalition forces in the volatile east region of the country. Violence in southern and eastern Afghanistan spiked last year, leaving about 1,600 people dead, including a surge in suicide attacks — a change of tactics by the militants.

Associated Press Writer Matthew Lee contributed to this report.