The spiritual leader of a militant group that claimed to have beheaded two American hostages in Iraq has been killed in a U.S. airstrike, and his Jordanian family is preparing a wake, a newspaper and Islamic clerics said Wednesday.

Sheik Abu Anas al-Shami, 35, was killed when a missile hit the car he was traveling in on Friday in the west Baghdad suburb of Abu-Ghraib (search), said the clerics, who have close ties to the family. They spoke on condition of anonymity.

Al-Shami was a close aide to Abu Musab al-Zarqawi, the leader of the militant group Tawhid and Jihad (search). The Al Qaeda-linked group is blamed for some of the biggest attacks in Iraq, including the bombing of the U.N. headquarters last year, and the beheadings of foreign hostages — including two Americans this week.

Al-Zarqawi is believed to have personally decapitated the American hostage Eugene Armstrong on Monday.

Al-Shami, a Jordanian of Palestinian descent who was also known as Omar Yousef Jumah, was believed to be the voice on several audio tapes that Tawhid and Jihad released via the Internet. In one such tape in August, a speaker identified as al-Shami said the militants planned to kill Iraqi Prime Minister Ayad Allawi (search), soldiers and police officers.

"We will not allow you to destroy our hopes in this blessed holy war, and we will not let you steal our bright tomorrow, which is now appearing on the horizon," the speaker said on the tape.

The independent Jordanian newspaper Al-Ghad quoted al-Shami's family on Wednesday as confirming the death. It said the family was preparing a wake in the east Amman suburb where al-Shami lived before he went to Iraq after the U.S.-led invasion last year.

The pan-Arab satellite television Al-Jazeera reported al-Shami's death earlier in the week, quoting unidentified relatives. A Jordanian security official said he could not confirm the death.

The clerics close to the family recalled al-Shami as a calm, flexible person of moderate ideology. They were surprised to hear he had joined Tawhid and Jihad. When he left Jordan last year, he told friends he was going to Saudi Arabia.

They said al-Shami was a leading member of a small Salafiyah movement in Jordan. The movement advocates the peaceful introduction of strict Islamic law, such as veils for women and gender segregation.

Al-Shami studied Islamic theology in Saudi Arabia and lived in Kuwait until the Iraqi invasion of 1990, the clerics said. After further Islamic studies in Medina, Saudi Arabia, al-Shami returned to Jordan and preached Salafiyah theology at an Amman mosque.

In the late 1990s, the government closed down an Islamic center that al-Shami had established in Amman on grounds that it was propagating a fanatical interpretation of Islam, according to the clerics and Al-Ghad newspaper.