A fifth package has reportedly exploded in Texas, this one at a FedEx facility in Schertz, which is outside of San Antonio. According to CBS News, federal officials say it is “more than possible” that the explosion is linked to the prior ones in Austin. 

The package was believed to be headed toward Austin, which has seen four bombings this month. Few other details — like when the package entered the system or where in Austin it was headed — were available. According to the Washington Post, one person was treated by medical teams at the scene and then released.  

The most recent Austin bombing occurred Sunday night and appeared to have been set off by a tripwire mechanism. Hundreds of law enforcement officials, more than 350 FBI agents, Texas Department of Public Safety troopers and bomb technicians from Houston and San Antonio are now working the case, according to local and state officials. 

Two people have been killed by the March explosions and four others have been seriously injured. Police believe the attacks are related. 

"We are clearly dealing with what we expect to be a serial bomber," said Brian Manley, Austin's interim police chief, at a Monday press conference. "The belief that we are dealing with someone who is using trip wires shows a higher level of sophistication, a higher level of skill.” 

Police noted, however, that there were differences in the attacks. The first three bombings in Austin were all detonated on the east side of Austin. The attacks appeared more targeted — packages were left at specific houses. The victims were people of color. Sunday night’s explosion seemed less targeted, investigators said. The victims were two white men in their twenties. 

Investigators said they didn’t know what the motive was for the attacks. 

“We don’t know why the bomber is doing this, we don’t know his reasons,” said Christopher Combs, special agent in charge of the FBI's San Antonio field office.  

Officials are offering a $115,000 award for information that leads to the arrest of the person or people responsible. Abbott also released $265,500 in emergency funding on Monday for Austin police to buy seven bomb-detecting x-ray systems. 

“I want to ensure everyone in the Austin region and the entire state that Texas is committed to providing every resource necessary to make sure these crimes are solved as quickly as possible,” Abbott said in a statement.