Two suspects in the killings of two Chinese students studying at the University of Southern California (USC) pleaded not guilty to murder charges Wednesday.

The two men, Bryan Barnes, 20, and Javier Bolden, 19, both from Los Angeles, were arraigned around 9:30 am local time in Los Angeles County Superior Court, where members from China's Consulate General and more than 20 USC students were attending the hearing.

Barnes and Bolden were accused of the April 11 killings of Qu Ming and Wu Ying, both 23-year-old USC students majoring in electrical engineering. The suspects were ordered to return to court on September 20 to determine when a preliminary hearing will be set.

A judge will determine at this preliminary hearing, where the Los Angeles police will attend to give their evidence of the case, whether there is enough evidence to require the suspects to stand trial.

The defendants' lawyer argued again that he has not been able to review all the information but the judge rejected the lawyer's appeal for another postponement.

Barnes and Boldento were ordered to remain jailed without bail. During the hearing, the judge had ordered them to stop talking to each other in the courtroom holding area.

In response to the court's decision, Yu Xiong, in charge of overseas Chinese affairs at China's Consulate General in Los Angeles, told Xinhua that the consulate hopes the suspects will be on trial as soon as possible and that, if guilty, they will be brought to justice for the sake of the victims and their families.

The shooting caused worries and rage in USC and other universities in southern California, where students from China launched a "Protect Our Safety" campaign.

Over 7,000 people have signed their names via the Internet to give their support to the victims and their families, as well as to call for school safety.

Representatives from the union of Chinese students and scholars have petitioned to the Los Angeles District Attorney's Office in the hope of having their voices heard.

Wang Haowang, chairman of Chinese students' and scholars' union in southwest America, told media that school safety is not only a concern of Chinese students but also for the whole international students' community as well as the USC and its neighboring areas.

"The tragedy did befall on two Chinese students and it is likely to happen to others in the future," Wang said, adding that he hopes the public could pay more attention to the case and make joint efforts to improve school safety.

The two suspects were arrested on May 18. They are facing charges of capital murder among other counts, the Los Angeles County District Attorney's Office announced earlier.

The two Chinese graduate students were gunned down on the 2,700 block of Raymond Avenue near the USC campus, where the female victim once lived, during a suspected robbery at around 1 am on April 11.

The suspects are also charged with attempted murder for allegedly shooting a 20-year-old man during a December 3, 2011 party in south Los Angeles. The complaint alleges both defendants used a handgun and caused great bodily injury.

Xinhua