AUSTIN, Texas – Explosions in Austin suppressed the excitement of the South by Southwest festival. 

Monday night, a suspicious package was found at the Austin Convention Center. The city shut down the downtown Metro Rail station as a precaution. Austin police later found the package was harmless and cleared the scene.

That was one of 150 calls officers responded to after two packages exploded on Monday. Those explosions killed a teenage boy and injured two women. 

PREVIOUS: Teen killed, two adults injured in two package explosions in East Austin

While these incidents all happened within Austin city limits, other Texas cities felt its effects.

Houston police warned residents to keep their guard up. Chief Art Acevedo said that while there are no immediate threats in Houston, residents need to be extra vigilant when receiving unexpected packages.

"A lot of us have family and friends in Austin and vice versa," he said. "We're very much connected as cities, we're very much connected as communities, and our thoughts and prayers are, obviously, with all the people of Austin as they experience the third explosion." 

San Antonio had a bomb scare Monday when an anonymous tipster told police that there were chemical explosives in a home.

It turned out to be harmless, but officers proceeded to tell the public to stay alert.

"The only way that we can stop these things from happening is if we have information on them," San Antonio Police Department Chief William McManus said. "But citizens who receive these packages can do themselves a huge favor that if they're suspicious of it, call us."

Austin police, with the assistance of the FBI and ATF, don't believe the explosions are connected to South by Southwest.

If you receive an unexpected package that seems suspicious, call 911.