Law enforcement personnel investigate the scene where the Texas bombing suspect blew himself up on the side of a highway north of Austin in Round Rock, Texas, U.S., March 21, 2018. (Xinhua/REUTERS)

HOUSTON, March 21 (Xinhua) -- A male suspect in a recent series of bombings in the U.S. city of Austin killed himself early Wednesday morning, local police said.

According to police, the man set off an explosive device in his car at the side of a highway after a Special Weapons and Tactics (SWAT) team had tracked down the suspect at a hotel near Round Rock, a city about 30 km north of Austin, police said.

The 24-year-old suspect's name won't be released until his family has been notified, Austin Police Chief Brian Manley said.

Austin area has been targeted by four package bombings since March 2 that killed two people and wounded several others.

The first bomb exploded while a man picked up a package outside his home in northern Austin. Ten days later, two more bombs went off in the eastern part of the city. The three explosives all together killed two.

Last Sunday night, two men were injured by an explosive device on a roadside near a fence about 16 km southwest of downtown Austin.

A fifth parcel bomb en route to Austin detonated early Tuesday, injuring one person at a FedEx distribution center near San Antonio, some 120 km southwest of Austin. Police later confirmed the explosion was not related to the other package bombings.