Trip wire may have set off latest bomb in Austin, wounding two

Two men on bicycles were wounded after a bomb exploded, possibly detonated by a trip wire, police said on Monday, as authorities continued to investigate three parcel bombs that killed two people earlier this month in the Texas capital.

The two men, thought to be in their 20s, suffered nonlife threatening injuries and were taken to the hospital on Sunday after they came upon a suspicious device on the side of a road in a residential neighborhood, Austin Police Chief Brian Manley said during a press conference.

The possibility that the roadside bomb was triggered when someone handled, kicked or came in contact with a trip wire, differed from the previous explosions that were set off when victims handled packages that were left on doorsteps, Manley said.

"We now need the community to have an extra level of vigilance and pay attention to any suspicious device," he said. "Given that there may have been a different triggering mechanism in this device, we wanted to get that out as early as possible."

"We're working on the belief that they are connected," Manley said.

Agents from the Federal Bureau of Investigation and US Bureau of Alcohol, Tobacco, Firearms and Explosives were at the scene, the FBI said on Twitter.

Investigators are trying to identify the person or people behind the three parcel bombs that exploded in three separate east side neighborhoods, killing two African-American males and leaving a 75-year-old Hispanic woman fighting for her life.

Austin police said whoever was responsible was trying to send a message and should contact authorities to explain any motive.

"We are not going to understand that (message) until the suspect or suspects reach out to us to talk to us," Manley said.

Manley said police were also investigating the bombings as possible hate crimes.

POLICE GET MORE THAN 7OO CALLS

The first bombing on March 2 killed Anthony Stephan House, a 39-year-old black man. It ripped a hole in a home entrance wall and damaged the front door.

A bomb last Monday morning killed Draylen Mason, a 17-year-old African-American teenager and budding musician, and injured his mother, who is in her 40s but was not further identified. A few hours later, a third bomb injured the 75-year-old Hispanic woman, who has not been identified.

The victims in Sunday's explosion were white, Manley told ABC News on Monday morning.

Police have received more than 700 calls about suspicious packages since the three parcel bombs, but authorities have not found any that posed a security risk, Manley said.

A reward of $115,000 has been offered for information leading to the arrest and conviction of the person or people responsible.