I wonder about the details here - I recall hearing he was killed by someone posing as a journalist whose camera contained a bomb.
Suspects in Masood Assassination Arrested
VOA News 26 Nov 2001 16:37 UTC
A Tunisian national has been detained in France and 11 other people in Belgium as part of a probe into the slaying of Afghanistan's Northern Alliance leader Ahmed Shah Masood. Commander Masood was assassinated in early September in his northern Panjsher valley stronghold by two Moroccans traveling on stolen Belgian passports and posing as journalists. The Moroccans exploded a booby-trapped camera while interviewing the commander in his office in northern Afghanistan.
A source close to the investigation says 11 other people believed to be members of the terrorist network that carried out the assassination were arrested early Monday in Belgium. Some analysts suspect that the September 9 assassination of Commander Masood was a go-ahead signal by terrorist network al-Qaida for the September 11 terror attacks in the United States.
Some information for this report provided by AFP and DPA.