Story highlights A note warning of a bomb was found in a bathroom, an official said

The main terminal of the airport was evacuated for two hours, the official said

Twelve flights were diverted or delayed, an airport spokeswoman said

The main terminal at Birmingham-Shuttlesworth International Airport in Alabama was briefly evacuated Sunday after a note was found warning of a bomb, officials said.

The evacuation was prompted by a note found in the men's bathroom at about 4 p.m. local time (5 p.m. ET), said Toni Bast, an airport spokeswoman.

The evacuation forced about 12 flights to be either diverted or delayed, Bast said.

The "all clear" was given shortly after 6 p.m. (7 p.m. ET), she said.

The evacuation comes just days after a gunman opened fire in the Los Angeles International Airport, killing a TSA officer and wounding three other people.