Austin Mayor Steve Adler: If you see anything suspicious, call 911

AUSTIN, Texas (KEYE) - Following a fourth explosion that rocked the city of Austin this month, Mayor Steve Adler is urging residents to call 911 if they see anything suspicious at all.

Speaking to "CBS Austin This Morning," Adler said, "If you're wondering whether or not to call 911, well, the answer to that question is yes."

The explosion Sunday night happened on Dawn Song Drive in the Travis Country neighborhood and injured two men. Austin Police Chief Brian Manley says it's possible the explosion was triggered by a tripwire.

Adler says both men hurt in the latest bombing are white, unlike the minority victims of the three previous attacks.