The Chechen guerrilla leader Khattab is a veteran of the Islamist struggle against Moscow, having earned his spurs against Soviet troops in Afghanistan 15 years before launching a "Holy War" in Dagestan.
Known only by his last name, Khattab, head of the "Islamic Army of Dagestan," is the loyal lieutenant of the Chechen warlord, Mr Shamil Basayev, with whom he has sought to restore a 19th-century Islamic state in the Caucasus.
"The Mujahideen of Dagestan are going to carry out reprisals in various places across Russia," Khattab said on September 3rd after Russian warplanes bombed Islamic strongholds in Dagestan.
The next day, a 300kg (660lb) bomb ripped through an apartment block housing military staff in the southern Dagestani city of Buinaksk, killing 64 people.
But while the Russian Interior Minister, Mr Vladimir Rushailo, has blamed Khattab and Basayev for that blast and two bomb attacks on Moscow apartment blocks which have killed more than 200 people, Basayev has categorically denied that either man was involved.
Khattab is a figure shrouded in mystery. Russian newspapers say he is 34, was born Habib Abder-Rakhman, and is of Jordanian or Saudi origin. He has been based in Chechnya since the 1994-'96 war of independence from Moscow.
Khattab began his military career 15 years ago, abandoning his studies at a US university to fight Soviet forces in Afghanistan.
In 1992 he fought in Tajikistan with the Islamic opposition against the Communist-backed regime in Dushanbe, moving to Chechnya in 1995 where he set up the first training camps for Chechen Islamists.
Viewed as one of the main proponents of Wahhabism, an austere brand of Islam in Chechnya and Dagestan, Khattab shares with Basayev the dream of recreating a 19th-century Islamic state which would "free all Muslims in the Caucasus."
Appointed head of the "Islamic Army of Dagestan," Khattab led some 2,000 rebels into Dagestan from Chechnya on August 7th, seizing control of several villages and declaring an Islamic republic. The insurgents fell back into Chechnya on August 24th after weeks of bloody fighting with government troops, only to return in force on September 5th. The string of terrorist attacks in Moscow coincided with the apparent crushing of Islamist resistance in Dagestan.
Round-faced with a large black beard, his thick black hair worn long under a green beret, Khattab for many Russians is the personification of the Islamic threat.
However, even in Chechnya Khattab is not universally popular, having escaped three assassination attempts since his arrival, the most recent in 1998.