An operational emergency at a federal nuclear weapons plant in Texas has ended without incident.

The Energy Department's Pantex plant near Amarillo said Tuesday in a tweet it was experiencing an unspecified emergency related to what it said was a "security event" and had mobilized an emergency response team.

Moments later the plant, which manufactures and disassembles nuclear bombs, said in a tweet the "security event at Pantex has ended without incident."

Carson County Judge Dan Looten said the east side of the plant had been affected and that officials had closed a local highway. Looten said the plant was not evacuated, but declined to provide more details on the nature of the emergency, which was reported at 11 a.m. local time.

A bomb team from the Amarillo Police Department responded to assist, Cpl. Jeb Hilton said.

Pantex didn't immediately respond to requests for comment.