At least 14 people died and 17 were injured after a shooting at the Inland Regional Center for People with Disabilities in the Californian city of San Bernardino.
"The two suspects – a man and a woman – were killed in a black car in which they were hiding. They were heavily armed," RIA Novosti cited a local police chief as saying.
However, he said that a "third man who was running away from the scene" has been sited, but the police do not know his role.
Later, media reported that the police have identified one of the attackers as Syed Farooq. The motive of the criminals has not been determined yet.
"There is a possibility that the motive could be linked to terrorism, but at the moment we do not know exactly," the representative of law enforcement forces said.
"A senior federal official who is monitoring the case said investigators believe one of the shooters left the party after getting into an argument and returned with one or two armed companions," the Los Angeles Times newspaper writes.