Fifth package bomb explodes in Texas at FedEx facility in San Antonio

A package bomb has exploded at a FedEx distribution facility in San Antonio city in Texas, hurting one person, officials said on Tuesday.

The package bomb exploded Sunday night and appeared to have been set off by a tripwire mechanism, they said.

It is more than possible that the explosion is linked to the prior ones that took place in Austin, as the package was believed to be headed toward that city, which has witnessed four bombings this month, the officials added.

According to local and state officials, hundreds of law enforcement officials, more than 350 FBI agents, troopers from Texas Department of Public Safety and bomb technicians from Houston and San Antonio were working on the case.

Two people have been killed and four others injured in the package bomb explosion which took place last month.

"We are clearly dealing with what we expect to be a serial bomber," Austin's interim police chief, Brian Manley told a 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, he added.

Police, however, noted that there were difference in the attacks as the first three bombings took place on the east side of Austin.

Investigators are yet to ascertain the motive behind the attacks. We don't know why the bomber is doing this, we don't know the reasons, said Christopher Combs, special agent in- charge of the FBI's San Antonio field office.

A reward of $115,000 has been announced by the authorities for providing information about the accused.

Also, $265,500 from the emergency funds was released by the authorities for Austin police to buy seven bomb-detecting x-ray systems.