Profile: Fazul Abdullah Mohammed
Fazul Abdullah Mohammed, reported to have been killed in the Somali capital Mogadishu, has long been one of the most wanted al-Qaeda suspects.
He was indicted by the US government for his alleged involvement in the 1998 US embassy bombings in Kenya and Tanzania.
He is also thought to have masterminded the simultaneous attacks on the Paradise Hotel in Mombasa and a missile strike on an Israeli charter flight in 2002.
Fazul Abdullah Mohammed is on the US Government's list of 26 "most wanted terrorists" and has a $5m (£3m) bounty on his head.
The US believes he is one of many "foreign terrorists" given shelter in Somalia and had asked the Somali group that now controls Somalia's capital to hand him over - despite repeated denials from Union of Islamic Courts that it is not harbouring foreign Islamic fighters.
Fazul Abdullah Mohammed first came to the attention of US investigators after the East Africa embassy attacks.
He is said by the FBI to be a master at using aliases, having evaded the agency for years.
He is thought to have headed home to the Comoros islands in the Indian Ocean immediately after the attacks, but as FBI agents tried to trace him there, he boarded a plane to the Gulf and disappeared without trace.
According to Ahmed Rajab, editor of the magazine Africa Analysis which has published reports on Mr Mohammed, the FBI says that during a search of Mr Mohammed's home, investigators found computers that contained evidence linking him to the al-Qaeda network.
They also claim to have found a number of passports of different nationalities.
Mr Mohammed was born in the Comoros islands in the early 1970s. He is thought to have spent some time studying in Saudi Arabia.
The Combating Terrorism Center at West Point military academy in New York has obtained a passport of Fazul Abdullah Mohammed issued in 1990 in Moroni and renewed in Jeddah, Saudi Arabia, in 1996.
It shows he travelled to Mauritius in 1990, to Tanzania in 1994 and 1995, to Sudan on several occasions in 1995, to Yemen in 1995, and to Kenya in 1993 and several times in 1994 and 1995. It shows he was also a resident of Pakistan for one year in 1991-1992.
Little more is known about him until he surfaced in East Africa in the late 1990s.
Like many suspected al-Qaeda operatives, he was able to exploit the region's lax law enforcement and porous borders to move around and avoid detection. He held Kenyan and Comorian citizenship.
According to reports, US agents believed they had tracked him down to Monrovia, the capital of Liberia, after the 11 September 2001 attacks on the US.
He was allegedly identified as one of a number of suspected al-Qaeda operatives to have set up base in Monrovia, as part of a plot to funnel diamonds and weapons through West Africa.
It is believed that from 2002 he was put in charge of al-Qaeda's operations in the whole of east Africa.
According to a report published in 2002 after a joint investigation by European intelligence agencies, the Pentagon planned to send a special forces team to Africa to snatch Mr Mohammed, but had to abandon the plot because his identity could not be confirmed.
In 2007 there were reports that Fazul Abdullah Mohammed had been killed in a US air strike in southern Somalia, but US officials later discounted the claims.
Before sightings by Kenya security operatives in Somalia, his last known whereabouts were on the island of Lamu off the north-eastern Kenyan coast where he was posing as a Muslim teacher, Ahmed Rajab says.
Mr Mohammed was said to have taken on a different name and got married there.
The FBI's website says he speaks French, Swahili, Arabic, English and Comoran and describes him as a casual dresser.
"Mr Mohammed likes to wear baseball caps. He is very good with computers," his profile says.