Authorities believe at least 14 people were killed and 17 people were injured when multiple shooters unleashed gunfire in a center for the developmentally disabled in San Bernardino, Calif., authorities said. Two suspects in the shooting are dead after a shootout with police.

The violence erupted around 11 a.m. Wednesday morning in San Bernardino at the Inland Regional Center, which provides services for people with disabilities. San Bernardino Police Chief Jarrod Burguan said that up to three people entered the building and opened fire on the people inside in an attack that lasted around five minutes.

The suspects were armed with long guns and fled in a dark colored car. Two suspects, one male and one female, driving a dark SUV were killed after a gun battle with police in a residential neighborhood near the site of the shooting, Burguan said at a press conference late Wednesday. According to the police chief, the suspects were dressed in “kind of assault style clothing,” and armed with assault-style rifles and hand guns. A third person running away from the shootout was detained, but police are not sure they were involved. A police officer working on the case was “struck” but has non-life threatening injuries, according to the San Bernardino county sheriff’s office.

Burguan added that authorities found what they believe could be a potential explosive device at the site of the shooting and the bomb squad was currently working on the situation. David Bowdich, FBI assistant director for Los Angeles, said that there was a possibility the shooting was an act of terrorism, but “we don’t know that yet.”

The Associated Press previously reported that police were serving a search warrant on a home in Redlands, California, in connection with the shooting.

According to the center’s president and CEO Maybeth Feild, the shooting took place in a conference area that had been rented out for a banquet by the San Bernardino County Department of Public Health.

“Most of the victims were essentially located in one area of the facility,” Burguan said, adding that some of those shot had “significant injuries.”

“These are people who came prepared” Burguan said. “They came in with a purpose.”

At a minimum, he added, the shooting was a “domestic terrorism-type situation.”

Ports and local county and city buildings were locked down, he added. The FAA put a flight restriction in place in the airspace above the city.

Witnesses said that more than 100 police officers had flooded the scene, according to the Associated Press. Terrified workers in the building said that they were forced to lock themselves in their offices until police arrived and instructed them to leave.

Dozens of people were seen leaving the area on foot, holding their hands in the air, while others were taken away on gurneys, the AP said.

The Los Angeles Times said one of the wounded was Kevin Ortiz, who was shot twice in the leg and once in the shoulder, according to his father.

“Kevin called me immediately after he got shot and said ‘I’ve been shot three times dad. I’m in pain. Don’t worry. There’s a policeman with me,” Carlos Ortiz, 54, told the newspaper.

A spokeswoman for the Loma Linda University Medical Center said that the hospital had received four adult patients from the shooting about 1 p.m. and was expecting another three, but could not speak about their conditions. Five people were being treated at the Arrow Medical Center and one had been discharged, officials said.

Authorities warned locals to avoid the area.

The San Bernardino city fire department said it was responding to reports of 20 victims in the shooting. The FBI also confirmed that it was on the scene.

Terry Petit told the AP that he received a text from his daughter as she was hiding from gunfire. “People shot. In the office waiting for cops. Pray for us. I am locked in an office,” she wrote, according to Petit.

The Inland Regional Center serves about 30,000 developmentally disabled people, including children, each year, according to Nancy Lungren, a spokeswoman for the California Department of Developmental Services, which runs the facility.

About 640 employees work out of the building in San Bernardino, she told TIME.

President Barack Obama once again called for gun reforms in the wake of the shooting, saying that the country could take steps to ensure that fewer mass shootings happen. “The one thing we do know is that we have a pattern now of mass shootings in this country that has no parallel anywhere else in the world,” he said.

California Gov. Jerry Brown canceled the state capitol’s annual Christmas tree lighting ceremony in the wake of the shooting.

“Our thoughts and prayers are with the victims’ families and everyone affected by the brutal attack,” he said in a statement. “California will spare no effort to bring these killers to justice.”

Get The Brief. Sign up to receive the top stories you need to know right now. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Write to Mathew Katz at matt.katz@time.com.