The United States will be attacked because of its prosecution of al-Qaida member Aafia Siddiqui, who is now serving an 86-year federal prison sentence, and Muslims must "take revenge" on those who imprisoned her, the No. 2 official of al-Qaida said in an Internet posting.

Ayman al-Zawahiri, the deputy to al-Qaida leader Osama bin Laden, said Muslims will fight the United States "until the Day of Judgment or until you stop your crimes."

Siddiqui was arrested in July 2008 for trying to kill U.S. troops and employees in Afghanistan. She was convicted in February in federal court in New York and sentenced to 86 years in September.

Because of its role in capturing, convicting and imprisoning Siddiqui, Zawahiri wrote that the United States risks retaliations. "So imprison whoever you wish, and kill whomever you wish, and bomb whomever you wish, and be as domineering as you wish, for the Ummah of Islam is behind you: bombing for bombing, and killing for killing, and destruction for destruction, and attacking equally."

Siddiqui is a former resident of the United States who obtained biology and neuroscience degrees from Brandeis University and the Massachusetts Institute of Technology. She moved back to Pakistan in 2002. Her second husband's uncle is Khalid Sheikh Muhammad, the alleged mastermind of the 9/11 attacks.

Islamist groups in the U.S. championed Siddiqui's case, claiming her "conviction is seriously flawed and her kidnapping and detention is a grave violation of human rights and international law." The Muslim American Society (MAS), urged people to attend her sentencing hearing as a sign of support.