PALM SPRINGS, Calif. — Many things remain unknown after one person was killed and at least four other people were injured in a vehicle explosion outside of a fertility clinic in Southern California in what the FBI called an “intentional act of terrorism.”

The blast on Saturday shattered windows and created an expansion debris field in Palm Springs. The investigation is expected to last several days as federal bomb experts collect and piece together evidence.

“Make no mistake, this is an intentional act of terrorism,” Akil Davis, assistant director in charge of the FBI’s Los Angeles Field Office, told reporters during a news conference Saturday evening. He said investigators believe the clinic was targeted.

The person who was killed was near the vehicle involved in the explosion, Davis said. However, he said authorities are still working to confirm the identity of the person who died and declined to say whether the person who died is the suspect in the blast.

“We’re not prepared to comment on that at this moment,” Davis said. “We’re not prepared to provide any additional comments on the relationship between the decedent and our person of interest.”

In response to a question from a reporter later, Davis said, “We have a person of interest in this investigation, but we are not actively out searching for a suspect.”

The explosion in the 1300 block of Indian Canyon Drive happened around 11 a.m., rocking nearby buildings and leading to a fire and the collapse of a building, according to authorities. The debris field covered over 250 yards.

Davis said the blast was “probably one of the largest bombing investigations that we’ve had in Southern California,” comparing it to the 2018 bombing of an Aliso Viejo day spa that killed one person and severely injured two other people.

The fertility clinic near the blast, the American Reproductive Centers of Palm Springs, sustained the brunt of the damage from the blast, including a gaping hole through the building.

The bomb detonated in the back parking of the clinic, where the remains of a burning car were found, along with a body on the adjacent street.

The clinic was not open at the time, so no employees or patients were inside the building. Despite the damage it sustained, the ARC said in a statement that none of the eggs, embryos and reproductive materials were unharmed in the blast.

“ARC will be fully operational on Monday morning, and our team is here to answer any concerns you may have. We appreciate the incredible support from our patients and local community, as well as the swift action of Palm Springs Police, Fire, and emergency responders. This moment has shaken us-but it has not stopped us. We will continue to serve with strength, love, and the hope that brings new life into the world,’ ARC said in a statement.

Investigation in Twentynine Palms

While many questions remain, Palm Springs police are expected to provide an update into the investigation at a press conference scheduled for 10 a.m. local time Sunday.

Investigators on Saturday zeroed in on a property on Adobe Road and Siesta Drive in Twentynine Palms less than 60 miles away from the origin of the explosion.

The area was evacuated because of possible bomb-making material in that home.

Our sister station, ABC7 Eyewitness News in Los Angeles, spoke with one neighbor who was told by sheriff’s deputies to evacuate the area due to possible explosives behind his home.

While he said he didn’t know the neighbor, this was the last thing he expected in his neighborhood.

“I have kids and they come hang out at my house sometimes, and knowing that someone was building a bomb that close to where me and my kids are, it’s pretty scary,” said Thomas Bickel.

The FBI is still investigating the area and have not said when the evacuations will be lifted or if it is connected to the Palm Springs incident.

The Associated Press reported that sources close to the investigation said the person responsible for the explosion posted online their beliefs that the world should not be populated, potentially pointing to a motive.

ABC News’ Jack Date, Alexander Mallin and Ivan Pereira contributed to this report.