First responders and paramedics with Austin-Travis County Emergency Medical Services, the Austin Fire Department and the Austin Police Department are responding to an explosion in southwest Austin in the 4800 block of Dawn Song Drive.
Federal agents with the FBI and ATF are also on scene and aiding in the investigation.
Initially reports came in of two possible explosions.
St. David's South Austin Medical Center confirmed that they are treating the two following the explosion and says that they are in "good condition." Both patients are described as males in their twenties.
The Austin Police Department is asking everyone to avoid the area at this time.
Residents in the immediate area of the 4800 block of Dawn Song Drive are being asked to wait in their homes and follow instructions of police officers if and when given.
It is unclear at this time what caused the blast or if it was related to the previous ones.
Sunday night's explosion occurred far from the first three blasts, which happened in separate, suburban neighborhoods in the eastern part of Austin.
Earlier Sunday, the Austin Police Department held a press conference with federal agents from the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives to announce an increase in reward money for information relating to the bomb explosions in Austin, Texas.
The reward for information that leads to an arrest in this case is now $115,000.
There have been three explosions since March 2, 2018 that killed two people and wounded two others.
A package bomb exploded at an East Austin home on March 2, killing 39-year-old Anthony Stephan House. Then, on Monday, package bombs at two addresses in other parts of the city exploded, killing a 17-year-old, wounding his mother and injuring a 75 year-old Esperanza Herrera.
No arrests have been made at this time.
This is a developing story and will be updated with more information as it becomes available.