Eleven Muslim students arrested for disrupting a speech by Israeli U.S. Ambassador Michael Oren at the University of California, Irvine pleaded not guilty to misdemeanor charges.

The students were arraigned April 15 in Orange County Superior Court on charges of conspiracy to disturb a meeting and misdemeanor disturbance of a meeting.

During Oren’s Feb. 8, 2010 speech, the 11 defendants stood one by one and shouted at the ambassador, calling him a “mass murderer” and a “war criminal,” among other insults. The disruptions, organized to protest Israeli actions in Gaza, prompted Oren to walk off the stage twice.

Eight of the defendants were students at UC Irvine and were members of the Muslim Student Union, which was suspended by the university for a year. The others attended the University of California, Riverside.

If convicted, the students could face a sentence up to a year in jail or lesser punishments including probation with community service and fines.

The trial is scheduled to start Aug. 15.