The parents of the suspects connected to the foiled explosive attack outside MacDill Air Force Base in Florida last month are illegal immigrants, the Department of Homeland Security announced, adding that the case underscores the dangers of birthright citizenship.

ICE agents took the parents, identified as Qiu Qin Zou and Jia Zhang Zheng, into custody on March 18, days after their son, Alen Zheng, allegedly planted an explosive device outside the base.

Officials said the parents illegally entered the United States and applied for asylum in 1993, but an immigration judge denied those claims and ordered both Zheng and Zou removed from the U.S. in 1998.

The Board of Immigration Appeals denied multiple attempts by the pair to reopen their case, but they remained in the U.S. for decades despite the removal order.

MIKE DAVIS: SANITY MUST BE RESTORED TO BIRTHRIGHT CITIZENSHIP

The arrests add a new dimension to the case, as the Trump administration argues it underscores national security risks tied to birthright citizenship, an issue now before the Supreme Court.

Their children — Alen Zheng and his sister, Ann Mary Zheng — were both born in the U.S. and are citizens.

Federal authorities allege Alen Zheng planted an improvised explosive device outside the MacDill Air Force Base visitor center in Tampa on March 10, while his sister later helped cover up the crime.

Prosecutors said Ann Mary Zheng "assisted after the fact" and tampered with evidence to hinder her brother’s arrest.

Federal investigators believe Alen Zheng fled to China and remains there. His sister was arrested after returning to the U.S. through Detroit.

The explosive device, described by officials as potentially "very deadly," failed to detonate and was discovered six days later by an Air Force airman.

Investigators later linked the device to materials recovered from Zheng’s home and a burner phone used to place a cryptic 911 call warning about the bomb.

DHS officials said the case highlights broader concerns about immigration enforcement and citizenship laws, as the Supreme Court weighs the scope of birthright citizenship under the 14th Amendment.

"Automatically granting citizenship to children of illegal aliens born in the U.S. … poses a major national security risk," DHS Acting Assistant Secretary Lauren Bis said in a statement. "This incident underscores the severe national security threat that illegal immigration and birthright citizenship pose to the United States."

The agency noted that the suspects were born in the United States after their parents entered the country illegally.

President Donald Trump moved to restrict birthright citizenship through an executive order signed on his first day in office, arguing the current interpretation of the Constitution is flawed.

The policy is being challenged in the Supreme Court, setting up a major legal battle over the scope of the 14th Amendment.

Federal prosecutors have charged Alen Zheng with attempted destruction of government property by fire or explosion, as well as weapons-related offenses, which could carry up to 40 years in prison.

Ann Mary Zheng faces charges of accessory after the fact and evidence tampering, with a potential sentence of up to 30 years.

Officials have not publicly identified a motive or confirmed any connection to the Chinese government.

MacDill Air Force Base houses U.S. Central Command and U.S. Special Operations Command, making it one of the most strategically significant military installations in the country.

Fox News' Alex Nitzberg and Alexandra Koch contributed to this report.