Updated at 7:05 p.m.: To include reports of possible video and an unexploded bomb.

AUSTIN — Police investigating the serial bomber terrorizing Austin may have several new leads, including surveillance video that “could possibly” show the suspect.

U.S. Rep. Michael McCaul, an Austin Republican, told the Associated Press on Tuesday about the potential video evidence. The footage, he said, may show the suspect at a FedEx distribution center south of Austin, where a package bomb exploded early Tuesday morning.

Also Tuesday, another congressman said FedEx has turned over what is believed to be a second bomb, this one intact, to investigators. The package could yield important clues about the identity of the perpetrator.

"They're trying to figure out how to open the package without destroying it," U.S. Rep. Lloyd Doggett, D-Austin, told the Austin-American Statesman.

Police confirmed Tuesday that all the explosive devices that have targeted Austin this month are connected. With no suspect named, anxiety and fear has deepened with each new blast. But Tuesday’s developments — and the two potential clues — are the most significant in the case since the bomber targeted the first victim March 2.

No one was injured in the blast that ripped through the FedEx distribution center in Schertz just after midnight Tuesday. But the explosion marked the fourth bombing in a week and the second in just three days, a striking upswing in the attacks on Texas’ capital city.

Unlike the first three Austin bombings, which killed two and injured four, the two devices discovered Tuesday did not cause any substantial damage. Both were sent by the same person, FedEx confirmed, adding that it gave investigators “extensive evidence” about the packages and who shipped them.

Both the bomb and suspicious package were also sent from the same location, a FedEx Office store southwest of Austin. This location is just a few minutes' drive from the site of the Sunday bombing that injured two men in their 20s.

The first three package bombs, for example, appeared to target specific addresses and were not randomly placed. But Sunday night's explosion was triggered by a tripwire, with no specific target apparent, Manley said.

Police have withheld specifics on the explosive devices to maintain the integrity of the investigation, he added.

"We were intentionally non-descriptive when we would put out descriptions of these devices," Manley told a meeting of the Austin City Council. "We didn’t want to give a false sense of security.

“We knew all along the devices could change.”

When the first bomb exploded earlier this month on Anthony Stephan House’s porch, killing him, police thought it was an isolated incident.

Then, on March 12, a second bomb killed 17-year-old Draylen Mason and sent his mother to the hospital. A third bomb that went off that same day severely injured Esperanza Herrera, 75, and law enforcement jumped into action.

Hundreds of federal agents descended on Austin. They are partnering with local police and the Texas Rangers and offering a $115,000 reward to help track down the bomber, in what McCaul, chairman of the Homeland Security Committee, called "probably the biggest investigation since the Boston bombings."

President Donald Trump addressed the attacks Tuesday and pledged to continue providing federal resources to help find the perpetrator.

"These are sick people and we will get to the bottom of it," Trump said, adding that the federal government has "a lot of power" to help local law enforcement.

"This is obviously a very sick individual, or maybe individuals. These are sick people and we will get to the bottom of it," President Trump says of the Austin bombings pic.twitter.com/G4PJiOEonw — CBS Evening News (@CBSEveningNews) March 20, 2018

.@POTUS mourns for victims of the recent bombings in Austin. We are monitoring the situation, federal authorities are coordinating w/ local officials. We are committed to bringing perpetrators of these heinous acts to justice. There is no apparent nexus to terrorism at this time. — Stephanie Grisham (@PressSec) March 20, 2018

At a White House meeting on so-called sanctuary cities, McCaul thanked the president for sending 500 federal law enforcement personnel to Texas to help with the package bombing investigation.

The latest blast in Schertz, the Austin Republican said, could yield fingerprints and other evidence to narrow the search.

"This is terrorizing this city of Austin," McCaul said.

Staff writers Todd J. Gillman and Karen Robinson-Jacobs and The Associated Press contributed to this report.