There have been "multiple injuries and fatalities" in a shooting at an immigration facility in Texas, Department of Homeland Security Secretary Kristi Noem says.

The attack happened on Wednesday morning at a Dallas field office for US Immigration and Customs Enforcement.

"Details are still emerging but we can confirm there were multiple injuries and fatalities," Noem says in a post on X.

She adds that the shooter had died of a self-inflicted gunshot wound.

This is a breaking news story and we're working to gather more information, so stay with us.