Family members of the man charged with Sunday's attack in Boulder, Colorado, have been taken into custody, Department of Homeland Security Secretary Kristi Noem said Tuesday.

Noem made the announcement on X, calling the suspect, Mohamed Soliman, an "illegal alien" and "terrorist." He is facing multiple counts of attempted murder and a federal hate crimes charge for the attack that injured 12 people at a march supporting Israeli hostages.

"We are investigating to what extent his family knew about this heinous attack, if they had knowledge of it, or if they provided support to it," Noem said. "I am continuing to pray for the victims of this attack and their families. Justice will be served."

A DHS official said six people — Soliman's wife and children — were taken into ICE custody and will now be processed under expedited removal, which allows the government to deport migrants in the U.S. illegally without holding a court hearing.

Soliman is an Egyptian national who arrived in California in 2022 on a non-immigrant visa that expired in 2023, the Department of Homeland Security said. Officials said he filed for asylum in 2022.

The family had been living in Colorado Springs. FBI agents searched the home Monday morning.

At a news conference Monday, Mike Michalek, FBI special agent in charge of the Denver field office, said the family had been cooperative in the investigation so far. Officials said after Soliman was arrested, his wife took her husband's iPhone to the Colorado Springs Police Department.

The 45-year-old Soliman is accused of using Molotov cocktails and "makeshift flamethrower" in Sunday's attack, burning multiple victims, police and the FBI said.

Witnesses told investigators that Soliman yelled "Free Palestine" and "End Zionist" during the attack.

The injured victims include an 88-year-old Holocaust survivor.

The group that came under attack, Run for Their Lives, has been gathering for a walk on Boulder's Pearl Street Mall every week for over a year to raise awareness about the dozens of Israeli hostages being held by Hamas in Gaza.

Soliman is expected to appear in federal court Friday afternoon.