Package explodes at FedEx facility in Texas

The FBI and investigators from the Department of Alcohol, Tobacco and Firearms (ATF) are investigating an explosion at a FedEx facility in the state of Texas, the bureau confirmed Tuesday.

No one was injured in the blast in Schertz, the FBI's San Antonio field office said on Twitter. Schertz is just outside San Antonio -- about an hour's drive southwest of the state capital of Austin.

FexEx said separately one of its employees suffered "minor injuries".

The explosion is the latest in an area wracked by a string of four previous explosions authorities are blaming on a serial bomber. Police are still working to determine a motive for the string of attacks that have recently grown in sophistication.

Two people were killed and four others injured in Austin since the attacks began March 2.

Two male victims aged 22 and 23 were injured Sunday in Austin after a trip wire was activated.

The White House said President Donald Trump is mourning the victims and is closely monitoring the situation, thought it said there does not currently appear to be a connection to terrorism.

"We are committed to bringing perpetrators of these heinous acts to justice," spokeswoman Sarah Huckabee Sanders said on Twitter.

The Professional Golfers' Association is set to begin its Dell Technologies Match Play in Austin on Wednesday.