A bomb exploded outside a fertility clinic in Palm Springs on Saturday, killing one person and injuring four others in what federal authorities have called an act of terrorism.

The explosion tore through the downtown area, damaging nearby buildings and scattering debris for blocks. The FBI said it believes the clinic was deliberately targeted.

"Make no mistake, this is an intentional act of terrorism," said Akil Davis, head of the FBI's Los Angeles field office. "This is probably one of the largest bombing investigations that we've had in southern California."

Officials confirmed that one person near the clinic at the time of the blast was killed. Authorities are still working to identify the deceased.

"Asked whether the clinic was deliberately targeted, Davis answered: 'We believe so, yes.'"

Palm Springs Mayor Ron deHarte told AFP the explosion occurred in or near a vehicle parked outside the American Reproductive Centers clinic. Aerial footage showed the building’s roof had collapsed. Eyewitnesses reported seeing human remains near the scene.

The charred remains of a vehicle were found in a nearby parking lot, some distance from the explosion’s apparent epicenter. The force of the blast blew out windows and doors, damaged multiple rooftops, and sent debris more than 200 yards, according to Davis.

The cause of the explosion and specifics about the device have not been publicly disclosed. Local media, citing unnamed law enforcement sources, reported that the person killed may have been a suspect.

"Davis told reporters that though the FBI was working to identify the deceased, 'we are keeping that close hold in order to protect the integrity of the investigation.'"

The fertility clinic later confirmed no staff were injured in the blast.

"A statement posted on social media by the clinic said no staff had been hurt, and that its lab -- 'including all eggs, embryos, and reproductive materials -- remains fully secure and undamaged.' It said that 'a vehicle exploded in the parking lot near our building.'"

Reproductive services such as abortion and fertility treatment remain a flashpoint in the United States, and while violence against clinics is rare, it is not unprecedented.

President Donald Trump’s Attorney General Pam Bondi condemned the incident.

"'But let me be clear: the Trump administration understands that women and mothers are the heartbeat of America. Violence against a fertility clinic is unforgivable,' she said in a statement on social media."

Residents reported feeling the impact of the explosion throughout the city.

Matt Spencer, who lives near the site, told the Palm Springs Post he ran outside after hearing the blast.

"'In front of the building [the car] was blown clear across four lanes into the parking lot of [Desert Regional Medical Center],' he told the paper. 'I could see the back of the car still on fire and the rims, that was the only thing that distinguished it as a car.'"

The Center for Reproductive Rights condemned the bombing.

"'The history of violence against reproductive health centers is why clinics need protections and patients must feel safe,' its president Nancy Northup said in a statement."

Authorities have not released further details about potential suspects or a motive as the investigation continues.