An Iraqi refugee is being accused of attempting to make electronic transmitters in order to remotely detonate bombs at two Houston malls, a federal agent said Wednesday.

Omar Faraj Saeed Al Hardan was indicted on three charges related to the terror plot. The suspect pled not guilty in court Wednesday, The Associated Press reports.

U.S. District Judge Lynn Hughes decided to hold Al Hardan without bail, saying there was a significant risk the suspect would attempt to flee from authorities, if given the opportunity.

Al Hardan came to Houston from his native Iraq in 2009. At some point, he became a supporter of the Islamic State terror organization and began plotting to set off explosives in two of the city's major shopping centers, one of which was the popular Galleria mall.

According to testimony from Homeland Security Special Agent Herman Wittliff, Al Hardan was also learning how to make electronic transmitters to trigger the bombs. In a search of the suspect's apartment, authorities found many cellphones, which he reportedly planned to use for the plot.

"He wanted to build them (the transmitters) for ISIL," Wittliff said, referring to the Islamic State terrorist group.

"For what purpose?" prosecutor Ralph Imperato asked.

"So he could kill people," Wittliff said.

Witliff also testified that Al Hardan was communicating with another Iraqi refugee, Aws Mohammed Younis Al-Jayab of California. The two corresponded on Facebook Messenger throughout 2013 and 2014, discussing potential plans and strategies on how to provide support for ISIS.

The agent said the two men talked about getting weapons training and eventually traveling to Syria to join the ISIS militants. He also alleged that a confidential federal informant provided Al Hardan with training on how to use an AK-47 in November 2014.

The court heard excerpts from a recording of a conversation between the suspect and his wife, taken in 2014.

"Once I get the passport I will leave America, I will leave. I will make a widow of you," Al Hardan told his wife, according to the excerpt. "I will go to Syria. I am not wacko. I am not wacko. I am speaking the truth. I want to blow myself up. I want to blow myself up ... I am against America."

If convicted, Al Hardan could be sentenced to up to 25 years in prison.