The woman, in her 40s, was taken to an area hospital with injuries that were not thought to be life-threatening.
Authorities have not yet said if the blast Monday was related to another explosion on March 2 that left a man dead.
Police investigate at the 4800 block of Old Fort Hill road in East Austin, where a package exploded and killed a 17-year-old boy and injured an adult woman. "We can not rule out that hate crime is at the core of this, but we're not saying that that's the cause as well", said Brian Manley, Austin's police chief.
Manley said they believe the attacks are related because packages were left on the victims' doorsteps overnight, the Express-News reported.
The March 2 incident, initially investigated as a suspicious death but now considered a homicide, occurred at a house in the city's wealthy Harris Ridge neighbourhood, about 12 miles northeast of downtown.
Manley said that while investigators are still searching for a motive, the incidents are under investigation as possible hate crimes because the victims in both cases are African-American.
The FBI field office in San Antonio also said it was assisting Austin police with the investigation.
The Bureau of Alcohol Tobacco and Firearms said a national response team would join Austin police in the investigation.
"I want to assure all Texans, and especially those in Austin, that local, state and federal law enforcement officials are working diligently to find those responsible for these heinous crimes", he said.
An Austin TV station reported that the Monday explosion happened shortly before 7 a.m.at a location about 11 miles from the March 2 explosion. The package, which was not delivered by any mail services, reportedly exploded in the kitchen.
Houston police chief Art Acevedo retweeted Manley's tweet and warned Houstonians, "In light of the 3 incidents in Austin, please be vigilant when receiving any package you weren't expecting".
"We are having innocent people getting hurt across this community, and it is important we come together as a community to solve this", said Manley.
In all three cases, he said, the packages did not appear to have gone through the U.S. Postal Service or private carriers like UPS.
Festival organizers did not immediately say whether they would be taking extra precautions, but the police chief urged attendees to "be aware of what's going on".
"We are not ruling anything out at this point", said Manley, who said the intended targets were not clear since multiple people live in the homes where explosives were placed. If you see a package, he reiterated: "Do not move it, do not touch it, call us".
The explosions happened far from the main events of the wildly popular festival known as SXSW, which brings about 400,000 visitors to Austin each year. The first two explosions occurred in the early morning hours.