A detainee has died and two others are critically injured after a rooftop sniper opened fire at an Immigration and Customs Enforcement (ICE) center in Dallas, Texas, officials say.

The gunman fired indiscriminately at the ICE facility and at a nearby unmarked van, law enforcement officials say, before dying from a self-inflicted gunshot wound.

No law enforcement were injured. FBI Director Kash Patel posted a photo on X of unused ammunition recovered from the scene. One casing has the phrase ANTI-ICE on it.

It is the latest in a string of attacks on ICE facilities in recent months as the agency ramps up efforts to deliver on US President Donald Trump's pledge for mass deportations.

While the investigation is ongoing, an initial review of the evidence shows an ideological motive behind this attack," Patel wrote on X. These despicable, politically motivated attacks against law enforcement are not a one-off.

Dallas police said officers responded to an assist officer call at the facility around 06:40 local time (11:40  GMT). The Department of Homeland Security (DHS) said three detainees were shot. One has died, and two were critically injured, it said. They remain in critical condition, officials later said.

Acting ICE director Todd Lyons identified the shooter as 29-year-old Joshua Jahn, who died of a self-inflicted gunshot wound, authorities said. Voter records indicate he was registered as an independent and last voted in the general election in 2024.

Jahn's brother, Noah, told NBC that his brother did not seem political. He said he last saw him two weeks ago and nothing seemed out of the ordinary.

FBI special agent Joe Rothrock told a news conference that rounds found near the gunman contained messages that are anti-ICE in nature.

This is just the most recent example of this type of attack, he said, adding the FBI was investigating it as an act of targeted violence.

The attack comes amid growing concerns in the US about political violence, with recent incidents involving ICE increasing tensions further. Political leaders have decried both the shooting and the divisive rhetoric that may have contributed.