One witness told the Biddeford Gazette, external that at around 07:20 local time, he saw lights flashing from an unmarked white SUV, and “at least two officers wearing green ICE vests”.

Lucas Scott, a Biddeford resident, said the agents were shouting as they surrounded a white sedan. He then heard at least four gunshots.

Another witness told the Associated Press (AP), external news agency that the man who was killed lived nearby with his wife and daughter.

“I watched a wife fall to her knees looking at her husband’s dead body on the ground,” Mary Hayes said.

“I watched a little girl crying with a little pink backpack on because she’s never going to see her father again.”

Senator King said that Mullin, the head of DHS, had told him the man was shot after attempting to drive his car at police.

“He was in a vehicle – pulled out in the vehicle, and the term the secretary used was ‘weaponised’ the vehicle and was shot by an ICE agent,” King said.

He added that officers involved did not wear body cameras, and that officials would be investigating whether deadly force was necessary.

“That’s what this investigation is all about and I certainly intend to stay after it to do everything I can to be sure the investigation is as transparent and thorough as possible,” King said, according to the AP.

The incident draws renewed scrutiny on DHS and ICE.

On 7 July, an ICE officer fatally shot 52-year-old builder Lorenzo Salgado Araujo as he was driving to a construction site in Houston.

Federal officials later acknowledged that the Mexican man was not the intended target of the enforcement operation, but they said he had tried to run over an ICE agent.

Mullin took over leadership of DHS in March, replacing Kristi Noem after she was fired by US President Donald Trump.

Noem’s tenure saw fatal shootings by immigration officers of two protesters, Alex Pretti and Renee Good, both American citizens.

The deaths of Pretti and Good came after the Trump administration announced immigration enforcement surges in Minnesota and other states.

Federal officials launched a similar operation in Maine, in January, dubbed Operation Catch of the Day.

Civil rights organisations filed a lawsuit against alleging aggressive tactics by federal agents during enforcement surges.