Two men have been charged this week with sexually abusing women seated near them on flights to Seattle.

The unrelated cases come at a time when the number of sexual assaults reported on planes has increased at "an alarming rate," according to the FBI.

The first incident was in January aboard a flight from London, and the second happened in March on a flight from Anchorage, according to federal prosecutors.

Babak Rezapour and Nicholas Matthew Stevens are accused of abusive sexual contact on an aircraft, which is punishable by up to two years in prison.

Rezapour appeared in US District Court in Los Angeles on Thursday. It's not clear whether a plea was entered. Stevens will appear in US District Court in Anchorage, Alaska, on Friday.

Court records did not indicate whether the men had attorneys. CNN was unable Thursday evening to reach either man. (CNN)