Nigeria, Feb. 22 -- War crimes suspect Alieu Kosiah shot and killed a teenage boy in Voinjama in 1994, a man claiming to have witnessed the incident, told the Swiss Federal Criminal Court on Saturday.

The 43-year-old-the sixth of seven "plaintiffs" to testify to Kosiah's guilt since his trial began in December last year-told the three presiding judges that Kosiah led a gang of rebels on a weekly killing spree, a routine that he called "Black Monday."

Kosiah invented the weekly killings of civilians as retaliation for the death of one of his men at a battle with the Lofa Defense Force, a militia formed to avenge their kinsmen, in Zorzor.

The boy who was murdered had refused to join other civilian captives in a car, the witness said.

"K...