ROUND ROCK, Texas — The suspect in the deadly bombings who terrorized Austin blew himself up early Wednesday as authorities closed in on him. He brought a grisly end to a three-week manhunt. Police warn that there may be more bombs out there.

The motive of the suspect remains a mystery. Moreover, it is unclear whether he acted alone in the five bombings in the Texas capital and suburban San Antonio that killed two people and wounded four others.

Authorities followed the vehicle, which ran into a ditch on the side of the road, he said.

When members of the SWAT team approached, the suspect detonated an explosive device inside the vehicle, the police chief said. The blast knocked one officer back, and a second officer fired his weapon, Manley said.

Austin Mayor Steve Adler thanked law enforcement for their work in bringing down the suspect and urged residents to continue to report anything that appeared suspicious or out of place.

A law enforcement official identified the dead man as Mark Anthony Conditt. The official, who has been briefed on the investigation, spoke to The Associated Press on the condition of anonymity because the official was not authorized to discuss the case publicly.

Police warned that there can be more bombs that need to be found.

“We don’t know where this suspect has spent his last 24 hours, and therefore we still need to remain vigilant to ensure that no other packages or devices have been left to the community,” Manley said.

Manley said the suspect is believed to be responsible for all the major Austin bombings.

Authorities initially believed the bombings may be hate crimes because the victims of the earliest blasts were black, but they backed off that theory after Hispanic and white victims from different parts of the city were also affected. The suspect was described as white.