Dallas: Two detainees were killed and one wounded in a sniper attack Wednesday on a US Immigration and Customs Enforcement (ICE) facility in the Texas city of Dallas, officials said.

The gunman, who opened fire "indiscriminately" on the ICE field office from the roof of a nearby building, died of a self-inflicted gunshot wound, the Department of Homeland Security (DHS) said in a statement.

The shooter's precise motive was still under investigation, but the FBI said he appears to have been directly targeting ICE, the agency chiefly responsible for carrying out President Donald Trump's pledge to expel millions of undocumented migrants.

"Early evidence that we've seen from rounds that were found near the suspected shooter contain messages that are anti-ICE in nature," FBI special agent Joe Rothrock told a press conference.

FBI Director Kash Patel published a photo on X of five unspent bullets -- one of which was marked with the words "ANTI-ICE" -- and denounced what he called "despicable, politically motivated attacks against law enforcement."

DHS said the shooter "fired indiscriminately at the ICE building, including at a van in the sallyport where the victims were shot."

Two detainees were killed and a third is in critical condition, it said.

The ICE facility which came under attack processes detainees before they are transferred to a long-term detention center, according to US media reports.

Homeland Security Secretary Kristi Noem and Vice President JD Vance condemned rhetoric directed at ICE since Trump's return to office.

"For months, we've been warning politicians and the media to tone down their rhetoric about ICE law enforcement before someone was killed," Noem said on X. "These horrendous killings must serve as a wake-up call to the far-left that their rhetoric about ICE has consequences."

AFP