Dallas, Texas - Officials revealed that a gunman opened fire "indiscriminately" on an ICE detention facility in Dallas, Texas, on Wednesday, killing two detainees and wounding another.

The gunman, who fired from the roof of a nearby building, died of a self-inflicted gunshot wound, the Department of Homeland Security 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.

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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 detained individuals were killed, and a third is in critical condition, it said.

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

ICE agents – often masked and unidentifiable as federal agents – have been carrying out raids on local communities across the country, and at least 14 people have died in ICE custody since Trump's inauguration.

Another facility in Texas was the target of an attack in July that left a police officer wounded in the neck, which came just days before a man armed with an assault rifle opened fire at a Border Patrol facility in McAllen, Texas.