A campaign plane carrying Ann Romney had to make an emergency landing in Colorado after the cabin filled with smoke, the Romney campaign said.

"All OK. Thank goodness," Romney campaign spokeswoman Andrea Saul said on Twitter.

The Republican presidential nominee's wife was headed to Los Angeles, but landed in Denver where emergency vehicles met the plane.

Saul tweeted that an electrical fire was the cause. She said Ann and Mitt Romney, who was in Las Vegas for a campaign event, spoke by phone after the plane landed.

Mrs. Romney was in Omaha earlier in the day. During a radio interview in Iowa yesterday, Romney lashed out at her husband's conservative critics, telling them to "stop it" for sniping about the GOP presidential nominee's recent travails, including remarks caught secretly on videotape.