A 28-year-old man running from “an encounter” with federal immigration agents at a gas station in St. Augustine, Fla., was struck and killed by a tractor-trailer on Tuesday morning, according to a state highway patrol spokesman.

It was not immediately clear whether the man interacted with the ICE agents, or if they were pursuing him.

The death happened shortly before 7 a.m. near a Wawa gas station on a busy thoroughfare. Agents from Immigration and Customs Enforcement and Homeland Security Investigations were at the station at the time, according to Sgt. Dylan Bryan, the Florida Highway Patrol spokesman.

The man who died had been inside a vehicle at the gas station with three other people who also fled, Sergeant Bryan said. The accident briefly snarled morning traffic along the road, about 35 miles south of Jacksonville.

The Department of Homeland Security did not immediately answer questions or release any information. The state highway patrol is investigating the traffic death. The man’s identity has not been released.

The whereabouts of the three others who had been in his vehicle were unclear on Tuesday afternoon. The vehicle was towed as part of the investigation, Sergeant Bryan said.

The incident unfolded amid increased scrutiny of federal agents who have recently intensified enforcement as part of President Trump’s aggressive immigration crackdown. The Trump administration has ordered a halt to most ICE traffic stops after two killings in which agents shot into vehicles.

On Monday, agents shot and killed a man in Biddeford, Maine. Agents had tried pulling over his car, which had just left a home they were monitoring, according to a Homeland Security statement. A spokesman for Senator Angus King of Maine said that Homeland Security officials told the senator that the man was not the person they were looking for.

Last week, an ICE agent fatally shot a Mexican immigrant, Lorenzo Salgado Araujo, during a traffic stop in Houston. Homeland Security later said that Mr. Araujo was not the operation’s intended target.