The charter plane ferrying Ann Romney from Omaha, Neb., to Santa Monica, Calif., on Friday was forced to make an emergency landing in Denver after the pilot reported seeing smoke in the cockpit.

The malfunction -- which Romney campaign aides said was mostly likely an electrical fire -- led the pilot of the Canadair Challenger 601 aircraft to divert to Denver around 2:40 p.m. Mountain Time, according to the Federal Aviation Administration.

Romney and several of her aides, as well as her Secret Service detail, disembarked using the plane's stairs. An aide to Mitt Romney tweeted a picture of firefighters boarding the small jet after it landed.

Andrea Saul, a Mitt Romney spokeswoman, tweeted that the plane had filled with smoke but said: "All okay. Thank goodness." Saul said the candidate and his wife spoke by telephone immediately after the plane touched down.

The Republican presidential nominee campaigned in Nevada on Friday, holding a luncheon fundraiser followed by a rally in Las Vegas.

Since the Republican National Convention in August, Ann Romney has maintained a brisk schedule of campaign events and fundraisers for her husband across the country. On Thursday, she held a rally for her husband's campaign in Milwaukee and a women's event in Clive, Iowa.

After campaign events Friday in Nevada and San Francisco, her husband will fly to San Diego, where the couple owns a home in La Jolla. He will campaign in Colorado on Monday before heading to New York for several campaign events and a planned Ohio bus tour next week.

Ann Romney will make an appearance Tuesday on "The Tonight Show with Jay Leno."