Reports: ICE arrests 8 suspected terrorists in New York, Philadelphia, LA

June 11 (UPI) -- Eight people from Tajikistan with suspected ties to a branch of the Islamic State have been arrested in New York, Los Angeles and Philadelphia after crossing the southern border into the United States, officials with knowledge of the operation confirmed Tuesday to media outlets.

U.S. Immigration and Customs Enforcement arrested the eight foreign nationals over the past several days on immigration charges, the sources told CBS News , ABC News and NBC News .

While no national security issues were uncovered when the eight individuals crossed the border last year and earlier this year, authorities said they later discovered through a wiretap that they had suspected ties to IS-Khorasan, or IS-K.

"Over the last few days, ICE agents arrested several non-citizens pursuant to immigration authorities," the FBI and the Department of Homeland Security said in a statement.

"The actions were carried out in close coordination with the FBI's Joint Terrorism Task Forces. The individuals arrested are detained in ICE custody pending removal proceedings," the statement said.

The FBI and DHS are currently working to have the eight migrants deported as officials said there is not enough evidence at this time to file terrorism charges. According to sources, the federal agencies said there is no active terror plot.

A senior Department of Homeland Security official told CBS News the eight migrants crossed into the United States without proper documents and were given notices to appear in immigration court.

The arrests come months after FBI Director Christopher Wray called on Congress to increase funding and warned about the "range of threats emanating from the border."

"Now increasingly concerning is the potential for a coordinated attack here in the homeland, akin to the ISIS-K attack we saw at the Russia Concert Hall," Wray testified in April .

"As the FBI and DHS have recently described in public and partner bulletins, the United States has been in a heightened threat environment," according to Tuesday's statement on the arrests.

"The FBI and DHS will continue working around the clock with our partners to identify, investigate and disrupt potential threats to national security."

According to the National Counterterrorism Center , IS-K is among the deadliest branches of ISIS, conducting attacks in Afghanistan and Pakistan as well as in Iran, Tajikistan and Uzbekistan while seeking to conduct similar operations in the United States and Europe.

It was sanctioned by the United States as a foreign terrorist organization in 2016.