Ayman al-Zawahiri took over leadership of al Qaeda in June 2011 after Osama bin Laden's death (CNN/Getty Images)
(CNN) -- Al Qaeda leader Ayman al-Zawahiri is calling on Muslims to kidnap Westerners, citing the success in the abduction of American aid worker Warren Weinstein in Pakistan.
In a two-part, more than two-hour video posted on jihadist web sites, al-Zawahiri called for the abductions as part of a vow not to "spare any efforts" to free Sheikh Omar Abdel-Rahman, the mastermind behind the 1993 World Trade Center bombing.
"God the great and almighty granted us success to capture the Jewish American Warren Weinstein," al-Zawahiri said in the video posted Wednesday, according to the terror monitoring group SITE Intelligence.
"We are seeking, by the help of God, to capture others and to incite Muslims to capture the citizens of the countries that are fighting Muslims in order to release our captives."
The video is the latest in a series released by al-Zawahiri, who was al Qaeda's No. 2 leader under Osama bin Laden. He took over leadership in June 2011 following bin Laden's death, according to statements posted on jihadist websites.
In the latest video, al-Zawahiri apologized to Abdel-Rahman, dubbed "the blind sheikh," for his imprisonment.
The Egyptian-born Abdel-Rahman was convicted in 1995 of conspiracy. He is serving a life sentence at a federal prison in North Carolina.
Al Qaeda claimed responsibility for the August 2011 abduction of Weinstein from his home in the Pakistani city of Lahore.
Months later, al-Zawahiri made a number of demands of the United States in exchange for Weinstein's release. Among the demands was the release of Abdel-Rahman.
In May, al Qaeda released a video of the 71-year-old Weinstein pleading with President Barack Obama to meet the demands.
"My life is in your hands, Mr. President," he said in the video. "If you accept the demands, I live. If you don't accept the demands, then I die."
U.S. officials have said Washington will not bargain with al Qaeda.
Weinstein was captured after his kidnappers managed to overcome the three security guards who were protecting him.
One of the FBI's most wanted terrorists, al-Zawahiri has played a defining role in al Qaeda. He is believed to be hiding somewhere in Pakistan's tribal region that borders Afghanistan.
He was indicted in absentia for his alleged role in the August 7, 1998, bombings of the United States Embassies in Dar es Salaam, Tanzania, and Nairobi, Kenya, that killed 224 civilians and wounded more than 5,000 others, according to the National Counterterrorism Center, part of the U.S. federal government.
The FBI is offering a $25 million reward for information leading to his capture, the same amount as the reward for bin Laden.
Al-Zawahiri's wife and three children were killed in December 2001 in a U.S. attack on the family's residence in Afghanistan.