The letter was the family's second attempt in 20 days to convince Jordanians that it has renounced all ties to the militant who has claimed responsibility for the Nov. 9 attacks on Amman hotels in which three suicide bombers killed 60 people and wounded hundreds of others.
Al-Zarqawi, whose real name is Ahmad Fadheel Nazzal al-Khalayleh, uses a name derived from the Jordanian city of Zarqa, where he was born, about 17 miles northeast of Amman.
He runs the Al Qaeda in Iraq group, which has carried out a campaign of bombings and kidnappings in Iraq. The United States has offered $25 million for information leading to his capture.
"We, the sons of the Bani Hassan tribe in all its branches in the Hashemite kingdom of Jordan, support and express solidarity with our cousins, the al-Khalayleh clan, and their decision to sever relations with the terrorist Ahmad Fadheel Nazzal al-Khalayleh, who calls himself Abu Musab al-Zarqawi," said the letter published in four leading newspapers.
"We condemn all terrorist actions carried out or claimed by this individual — actions which are alien to members of this tribe," continued the letter, which bore the stamps and signatures of more than 370 clan members.
The Bani Hassan is one of the largest of Jordan's nearly 100 major Bedouin tribes, which form the bedrock of support for the royal family. Its members hold senior posts in the army and other government departments.
Referring to the family of King Abdullah II, the letter added: "We reiterate our support for the Hashemite Crown which, God willing, will always be protected, and we uphold the pledge of our ancestors to be a sword in the hands of the noble Hashemite dynasty."
In a similar letter on Nov. 20, almost 60 members of al-Zarqawi's extended family disowned him and pledged fidelity to the crown.
Al-Zarqawi has claimed responsibility for several terror attacks in Jordan, including a plot to cause a chemical explosion that would have killed thousands of people, according to government experts. The plot was foiled in April 2004.
A Jordanian court condemned him to death in absentia for planning the attack that led to the 2002 murder of U.S. aid worker Laurence Foley.