A man who had threatened a Christian radio station was shot and killed by police Friday after he fired at officers with a rifle and tried to run them over with his sport utility vehicle, authorities said.

WTLR station manager Mark VanOuse said the station received a tip around 10 a.m. that someone armed with a shotgun was asking people for the address of the radio station and for money. Police got the same tip and went to the station, Centre County District Attorney Michael Madeira said.

Officers intercepted the man as he arrived at the station, where he began shooting at police outside, ramming police cruisers and trying to run over officers on foot, witnesses said. After an exchange of gunfire, the suspect was shot dead in his white Ford Bronco, Madeira said. No one else was wounded.

Witnesses said they heard about 20 rounds of gunfire.

"At least twice he fired from the car," said Brad Shearer, who watched from his office window across the street. He said he saw the man try to run over police officers with their guns drawn.

During a second exchange of gunfire, the gunman's vehicle drifted into a building, Shearer said.

The man, who has not been identified, is suspected of having had multiple weapons in the SUV, Madeira said.

VanOuse, who had taken his two employees to a secure room, said he saw only glimpses of what happened. The altercation lasted no longer than 15 minutes, he said.

"He was moving fast," VanOuse said. "He was blowing right past police cars with officers who had their rifles drawn."

He said he did not know why the station was targeted.

"There is nothing leading up to this point that would have given us any indication of someone being upset with us," VanOuse said.