The suspected Texas serial bomber has been killed during a confrontation with police, officials confirmed.
US media have identified the suspect as Mark Anthony Conditt, an unemployed 24-year-old who bought bomb-making materials at Home Depot.
Police chiefs said Conditt detonated a device as he was being pursued by police.
At a news conference, authorities said they had identified the suspect in the last 24 hours and located his vehicle.
As he drove away on Wednesday morning, police followed before the car ran into a ditch on the side of a road.
When members of a SWAT team approached, the suspect detonated an explosive device inside the vehicle. The blast knocked back one officer, while a second officer fired his weapon.
Two people have been killed and four others injured in four different explosions in Austin over the last 17 days.
A fifth explosion at a FedEx distribution centre placed the state on high alert.
A 39-year old man and a 17-year-old boy was killed and two women were injured in two separate parcel bomb blasts on March 12.
And on Sunday, two men aged 22 and 23 were injured in an explosion triggered by a tripwire.
Authorities had warned that the devices appeared to be getting more sophisticated.
"We are clearly dealing with a serial bomber," Austin Police Chief Brian Manley said. "We will have to determine if we see a specific ideology behind this."
Timeline of explosions:
- 2 March: Explosion takes place on the front porch of 39-year-old Anthony Stephan House's home in Austin. He later dies at a hospital nearby.
- 12 March: A 17-year-old dies and a woman left seriously injured after a package explodes at their home in Austin.
- 12 March: A second package bombing in the same day leaves a 75-year-old woman in a "critical, but stable condition."
- 18 March: Two men are injured after an explosion possibly caused by a trip wire.
- 20 March: A device explodes at a FedEx distribution centre near San Antonio - the only incident outside of Austin.
- 21 March: The 'serial bomber' suspect dies after detonating an explosive device inside his vehicle.