ROUND ROCK, Tex. — A suspect in the series of bombings that have terrorized the city of Austin, Tex., died early Wednesday, blowing himself up in his vehicle as officers closed in on him, the authorities said.

A law enforcement official identified the suspect as Mark Anthony Conditt, a 23-year-old white man.

Officials did not rule out the possibility that the man had accomplices.

“We do not understand what motivated him to do what he did,” said the Austin police chief, Brian Manley.

The first explosions hit African-American residents whose families are well-known in the city’s black community, though two white men were injured by an explosive triggered by a tripwire on Sunday. Chief Manley did not address any potential motive, including race.

Law enforcement officials cautioned that the bomber could have planted other explosives that have not yet detonated. “We still need to remain vigilant,” Chief Manley said. “We do not know where he has been in the past 24 hours.”

He added, “This investigation is still underway, so we cannot say that this was an individual acting on their own.”

The suspect lived in Pflugerville, a suburb of 59,000 about 20 miles northeast of downtown Austin, a law enforcement official said.

“There were several leads that led us to this person,” including surveillance video, Chief Manley said.

Police and federal agents Wednesday morning entered the home of Mr. Conditt’s parents in Pflugerville, a white clapboard, two-story home with an American flag hanging on the front porch. His parents had not answered several knocks on the door from reporters, but later in the morning, the agents pulled up in two vehicles and they were allowed in.

Gov. Greg Abbott, a Republican, told a local television affiliate that Mr. Conditt lived with two roommates, who were cooperating with the investigation.

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“Through those roommates, as well as being able to access social media accounts, as well as getting into the house and gathering information, we’re going to learn so much more over the next few hours,” Mr. Abbott said. “Before the sun sets today we will have so many other pieces of the puzzle.”

The suspect is believed to be responsible for at least six bombs that killed at least two people and wounded five. Four bombs detonated in various locations in Austin where they had been left. Another detonated at a FedEx distribution center in Schertz, Tex., near San Antonio, and a sixth was found, unexploded, in a FedEx facility near Austin’s airport.

The attacks started the morning of March 2, when a package bomb detonated on the porch of an Austin home, killing Anthony Stephan House, 39. That was followed 10 days later by two bombs that were found outside homes, one of which killed a 17-year-old boy.

The first three bombs were apparently detonated when they were picked up or jostled. Later, a package bomb exploded outside another Austin home, set off by a tripwire. The bombs at the FedEx centers were found on Tuesday.

“Within the past 24 to 36 hours, we started getting information on one person of interest,” Chief Manley said. “This person of interest ultimately moved to being a suspect.”

The suspect’s vehicle was traced to a hotel in Round Rock, just north of Austin, Chief Manley said, where a SWAT team surreptitiously surrounded the hotel and called other specialized units. But before those teams could arrive, the suspect drove away. 

Officers followed the suspect, who stopped in a ditch off Interstate 35, and SWAT officers approached the vehicle on foot.

“The suspect detonated a bomb inside of the vehicle, knocking one officer back” and slightly injuring him, the police chief said. Another officer fired his gun at the vehicle.

Michael Luna, a guest at a Red Roof Inn near the confrontation, told a local news channel that he heard the explosion from the bomb, which sounded as if it had gone off 100 to 200 yards from him, when he was outside smoking a cigarette in the parking lot. Mr. Luna, who said he had been in the military, said that the explosion sounded like two grenades going off at the same time, and that he heard a pop afterward that may have been gunfire.

The portion of Interstate 35 near that confrontation was a traffic nightmare for hours as commuters moved at a glacial pace in the southbound lanes, many of them presumably unaware of what had happened. State troopers barred access at several ramps along that stretch of the highway.

By Wednesday morning, aerial video footage of the area from KVUE, a local television affiliate, showed a red SUV with blown-out windows next to a blue tarp, surrounded by investigators’ vehicles.

Mayor Steve Adler of Austin said that the city’s residents should continue to watch out for suspicious packages that the bomber may have planted before his death. He expressed hope that residents who had been brought closer together during the attacks would continue to watch out for each other as the threat receded.