Al-Qaeda’s chief operational planner, Abu Obaidah al Masri, died due to an infectious disease in Pakistan, anti –terrorism officials said Wednesday. Al-Masri, suspected of orchestrating al-Qaeda plots including the London transportation bombings of 2005, is believed to have died of hepatitis C, the Los Angeles Times reports.

It appears that Abu Obaidah al Masri was a powerful chief of the terrorist network’s external operations, who trained recruits in hideouts in western Pakistan and sent them to carry out assaults against the West, according to the investigators. The strategist al-Masri was also responsible for attacks on U.S. forces in Afghanistan.

A U.S. official explained that the anti-terrorism investigators currently traced conversations among al-Qaeda activist, unveiling that al-Masri died of hepatitis C. He is believed to have died in Pakistan’s lawless tribal area bordering Afghanistan.

The Egyptian al-Qaeda boss was suspected in a plot to blow up commercial airplanes over the Atlantic Ocean in 2006, the Associated Press reports. British authorities arrested 24 suspects in August 2006, after almost a year of investigation. The terrorists masterminded to smuggle bombs and detonators disguised as electronic devices and drinks onto the airlines. The plot caused Britain and the U.S. to adopt tougher security measures for passengers. While the British banned for a time nearly all carry-ons, the U.S. limited the amount of liquids that could be brought on board.

The London transportation bombings on July 2005 occurred during the morning rush hour. Three bombs exploded simultaneously on the London Underground and the fourth one exploded an hour later on a bus. 52 people were killed and 700 wounded due to the attack. Four suicide bombers also died.

Believed to be in his mid-40s, Al-Masri lived in Germany in the 1980s before going to Afghanistan to fight the Soviet Army. He was also a veteran of wars in Bosnia and Chechnya, and emerged as one of the senior al-Qaeda operatives after the death of Abu Hamza Rabia, killed by a missile strike in Pakistan in 2005, according to Pakistani authorities. Al-Masri was also suspected of involvement in the November 1995 suicide bombing of the Egyptian Embassy in Islamabad. 17 people were killed in the attack.

Al-Masri appears as being one of the most mysterious members of the terrorist network’s inner circle, as U.S., European and Pakistani officials claim they do not know his real name. “Abu Obaidah al-Masri” is a nom de guerre, translated “father of Obaidah, the Egyptian,” the Washington Post reports.