Two brothers awaiting trial in South Florida on charges of plotting a terrorist attack in New York City are being accused of assaulting two deputy U.S. marshals.

Documents filed in the case of Pakistani-born Sheheryar and Raaes Qazi show the alleged attack occurred April 8. U.S. District Judge Robert Scola issued an order Wednesday setting a May 9 hearing says the incident happened at a secure facility where defendants can examine classified evidence.

"This incident is currently under investigation and may lead to the filing of additional charges," prosecutors said in a recent court filing.

The two men are already accused of several terrorism-related charges stemming from an alleged plot to blow up New York landmarks to avenge overseas deaths in U.S. drone attacks. Both brothers have pleaded not guilty.

Investigators found bomb-making materials and components at the Qazi family home in Broward County and Raees Qazi, 21, traveled to New York in late 2012 in hopes of finding a job and carrying out his plot, prosecutors have said. But he was unsuccessful and eventually returned to Florida on a Greyhound bus.

The documents say 31-year-old Sheheryar Qazi's lawyer, Ronald Chapman, may have to withdraw from the case because he witnessed the alleged attack and would have a conflict of interest if his client is charged with assault. Chapman did not immediately respond to an email seeking comment.

Scola said in light of the assault he wants the hearing next week to also focus on whether additional security is needed in his courtroom for the Qazi case or in the classified documents viewing location, known as the Secure Compartmentalized Information Facility or SCIF.

Trial for the two brothers is currently set for November. The case is also notable because of a legal battle over whether prosecutors must disclose if evidence from once-secret U.S. surveillance programs will be used against the defendants.


Follow Curt Anderson on Twitter: http://twitter.com/Miamicurt