AUSTIN, Texas – According to police, an explosion in Southwest Austin may have been caused by a trip wire leaving two men in their 20s injured.

Police were called to the 4800 block Dawn Song Drive at 8:42 p.m. Sunday, March 18.

In a press conference Sunday evening, Interim Austin Police Chief Brian Manley said very little is known, but that residents within a one-mile radius of the incident in the Travis Country neighborhood must stay inside and are urged to call 911 or APD's tipline as soon as possible if they see anything suspcious in the area. 

The emergency alert only applies to the 3,500 residents of the Travis Country neighborhood. 

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The two male victims in their 20s were transported to the *St. David's South Austin Medical Center with serious, but non life-threatening injuries.

Regents School of Austin has made the decision to implement a delay for Monday morning. 

Austin ISD has said they're working with the police to take appropriate measures and that buses will not be able to enter the neighborhood on Monday. 

While too soon to know if this fourth explosion is connected, the multiple organizations on scene including the FBI, ATF and Austin law enforcement, have been investigating 3 other explosions associated with left packages. The first explosion happened at 7 a.m. on March 2 killing 39-year-old Stephan House. The second and third explosions happened March 12. The second one killed 17-year-old Draylen Mason and injured his mother. Hours later, the third explosion injured a 75-year-old hispanic woman.

WATCH LIVE | Spectrum News , a 24-hour news station, is live from the scene and will continue to be on channels 1, 8 or 200 in Austin and 14 and 200 in San Antonio. Cable subscribers can also watch via the live-stream from your computer, smartphone and our mobile app

*Originally reported as San Antonio Medical Military Center.

Combined locations of four explosion incidents in Austin:
 

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