The father of slain US reporter Daniel Pearl has urged Muslims worldwide to reject violent extremism.
Daniel Pearl was kidnapped and beheaded in 2002
He was responding to media footage of the recent murder of Nick Berg, a US civilian beheaded by militants in Iraq.
Judea Pearl said Mr Berg's killing was "a similar attack on humanity" to the killing of his son, whose murder was also filmed by his captors.
Wall Street Journal reporter Daniel Pearl was kidnapped and killed by Islamic extremists in Pakistan in 2002.
"I am speaking to those who can win the minds of the young and faithful to the side of hope," wrote Judea Pearl in a commentary published by the Wall Street Journal.
He said his appeal was not addressing the men who have been accused of involvement in the murders of Mr Pearl and Mr Berg - namely, Saudi fugitive Osama Bin Laden and Jordanian militant Abu Musab al-Zarqawi.
His words, he said, were instead directed at Islam's intellectual and religious leaders, who were troubled at the hijacking of their faith by a violent minority.
"I beseech you to join the courageous Muslims who have denounced, in unambiguous language, not only the killing of Nicholas Berg, but the growing practice of killing innocent human beings as a means of communicating grievances," Mr Pearl wrote.
Daniel Pearl disappeared while chasing a story in the Pakistani city of Karachi.
The US embassy in Pakistan later received a video which showed Mr Pearl's captors cutting his throat.
Nick Berg was kidnapped while visiting Iraq in search of reconstruction work.
An Islamist website later posted grainy video footage of Mr Berg being decapitated at the hands of masked gunmen.
The gunmen claimed they were acting to avenge the abuse of Iraqi prisoners at the hands of US soldiers in Iraq.
In his piece for the Wall Street Journal, Mr Pearl's father expressed outrage at recent media images depicting the torture and humiliation of Iraqi detainees.
But he urged Muslim leaders to warn their followers against entering a "cycle of accusation" or emulating those who killed civilians in the name of Islam.
A "public outcry" amongst Muslims at the murder of western abductees would help "us create the conditions for mutual respect, not mutual accusation," he wrote.