The EIJ is led by Ayman al-Zawahiri, a man believed to be a close associate of Osama Bin Laden. Sheikh Omar Abdel Rahman, who has been convicted of conspiracy relating to the February 1993 bombing of the World Trade Center, is the spiritual leader of the group.
The group specialises in armed attacks against Egyptian Government personnel and official Egyptian and US facilities. The organisation is believed to have networks in Egypt, Afghanistan, Yemen, Pakistan, Sudan, Lebanon and the United Kingdom.
The original Islamic Jihad was responsible for the 1981 assassination of Egyptian President Anwar Sadat.
EIJ claimed responsibility for the attempted assassination of Egyptian Interior Minister Hassan al-Alfi in 1993. In the same year, the group attempted to kill Prime Minister Atef Sidqi.
Merger with al-Qaeda
It is also believed to have been responsible for a bombing in 1995 at the Egyptian embassy in Islamabad, and for a foiled 1998 attack on the US embassy in Albania.
Unlike Egyptís other militant Islamic group, the Gamaat al-Islamiya, the EIJ does not target middle and lower level security personnel, Coptic Christians, and Western tourists.
It is believed to have merged with al-Qaeda in the late 1990s.
US officials have made it clear that their campaign against international terrorism aims much wider that Bin Laden and his al-Qaeda organisation. Newspaper reports have described EIJ leader Zawahiri as prime suspect number two, after Bin Laden.
Zawahiri is also wanted in the US, along with Bin Laden, in connection with the US embassy bombings in east Africa.
Several of the 19 suspected hijackers named by the FBI are linked to EIJ. In particular Mohammed Atta, the suspected ringleader of the hijackers, is a known member of EIJ.