A helicopter plucked two convicted murderers and a thief from a state prison yard under fire from guards Monday and was chased across the skies by a U.S. Customs chopper as it tried to make a getaway, officials said.

The helicopter flew south, dropped off two people and then fled across the Albuquerque area, 60 miles south of here, officials said.The penitentiary of New Mexico was immediately locked down and a head count was under way to determine who had escaped, said Don Caviness, a spokesman for the New Mexico Corrections Department.

Caviness said the helicopter apparently flew into the area at a low altitude about 9:50 a.m. with a man and a woman aboard.

It picked up the three inmates and took off, flying away at low altitude as corrections officers blazed away. Caviness said it was not known whether any of the shots hit the helicopter.

The helicopter flew to Valencia County, about 80 miles south of here, unloaded two of the inmates, one of them injured, and took off again, said Ronni Crago, spokeswoman for the Bernalillo County sheriff's department.

Crago said one of the inmates was captured, while the other fled on foot and was being pursued.

"There are still an undetermined number of inmates in the helicopter that is being chased by a helicopter from the U.S. Customs service," said Crago.

"Those two helicopters just circled the downtown Albuquerque area," she said at 11:06 a.m. "We don't know if they are armed, but we are going on the assumption that they are armed and dangerous."

Department of Public Safety spokesman Dan Taylor said the New Mexico National Guard was also searching for the craft.

The three escaped inmates were identified as Daniel Mahoney, 30, of Hillsboro, Fla., serving life plus 60 years for second-degree murder and armed robbery; Francis Preston Mitchell, 26, of Summit County, Utah, serving life for first-degree murder; and Randy Mack Lackey, 19, of Curry County, N.M., serving a nine year sentence for larceny.

Caviness said Lackey was a helicopter pilot.