New York, Mar 21 (IANS): A suspect in a wave of bombing attacks in Texas capital city of Austin killed himself inside his car with an explosive device on Wednesday as authorities closed in on him, police said.

Since the bombings started on March 2, investigators hunted for clues, calling the attacks the work of a "serial bomber" who kept changing his tactics. The bombings killed two people and left Austin terrorized with fear for 19 days, CNN reported.

The police and the Federal Bureau of Investigation (FBI) tracked the suspect, a 24-year-old white male to a hotel parking lot in Round Rock, Texas, north of Austin, where they found him inside his vehicle, said Interim Austin Police chief Brian Manley.

As police waited for tactical units to arrive before engaging the suspect, he left the hotel in the vehicle. SWAT approached the vehicle and the suspect detonated a bomb, killing himself and injuring a SWAT member.

Investigators had broadened their efforts after a package exploded at a FedEx sorting centre near San Antonio on Tuesday and a second unexploded bomb was discovered the same day at another FedEx facility near Austin.

The two packages were connected to previous bombings that left two people dead. FedEx said the person who sent the package that exploded also shipped the second one that was turned over to law enforcement officials.

FedEx said it provided authorities with "extensive evidence" from its security system on the packages and the person who shipped them.

The first explosion in early March killed Anthony Stephan House, 39, when it detonated at his home. Ten days later, another explosion killed Draylen Mason, a college-bound 17-year-old known for his passion for music.

Hours after Mason was killed, another explosion seriously injured Esperanza Herrera, a 75-year-old woman visiting her elderly mother's house.

On Sunday, two more men were injured just hours after police made a plea for the bomber to come forward to speak to authorities.

A possible explosion reported on Tuesday night at a Goodwill store in Austin turned out to be unrelated. In that incident, an employee was injured by two "artillery simulators" in a donation box, said Austin's assistant police chief.

President Donald Trump had said "sick people" carried out the blasts.