Jan 17, 2010 6:43 PM EST

A group of American umpires working in the Dominican winter league resigned Sunday and were to leave the country because they feared for their safety.

Former major leaguer Jose Offerman swung at one of them recently, leading to their departure.

Daniel Rayburn, Jayson Bradley, Justin Vogel and Barry Larson gave notice Sunday to the Dominican League after an incident between Rayburn and Offerman.

"They left after filing their report of Saturday's incident," a source told ESPN.com.

Via ESPN