The father of an American believed to have been beheaded by Abu Musab al-Zarqawi said Thursday more killings will come out of the militant leader's death.

"I see more death coming out of al-Zarqawi's death," Michael Berg, the father of Nicholas Berg, told the Associated Press after learning the al-Qaeda in Iraq leader had been killed by a U.S. airstrike on Wednesday.

Michael Berg hugs his daughter Sara on May 11, 2004 after learning his son Nicholas had been beheaded.
Michael Berg hugs his daughter Sara on May 11, 2004 after learning his son Nicholas had been beheaded.
(Jacqueline Larma/Associated Press)
"His death will incite a new wave of revenge. [U.S. President] George Bush and al-Zarqawi are two men who believe in revenge," Berg said.

The CIA has said al-Zarqawi beheaded Nicholas Berg, 26, in May 2004. The communications worker from Pennsylvania had been in Iraq looking for business contacts.

A video showing Berg's beheading circulated on the internet. It was titled "Abu Musab al-Zarqawi Shown Slaughtering an American."

Michael Berg, a pacifist who is running on the Green Party ticket in Delaware for a seat in the House of Representatives, said  "the news of the loss of any human being is a tragedy. I think al-Zarqawi's death is a double tragedy."

Berg said he's not even sure al-Zarqawi was responsible for his son's death.