A leading woman missionary who worked with abandoned and orphaned children in Haiti has been shot dead.

Roberta Edwards, 55, director of SonLight Children's Home, was murdered in Haiti's capital Port-au-Prince while driving to a petrol station.

Her ministry was supported by Estes Church of Christ in Henderson, Tennessee. In a statement on its website, Estes said their hearts were "saddened" by the murder.

"On Saturday evening, Oct 10, witnesses report that Roberta's car was stopped by another vehicle which intentionally blocked her path. Armed gunmen emerged from the vehicle and fired into Roberta's car, causing her death. Haitian authorities are investigating, and the identity of the perpetrators and the motive are not known at this time. She is survived by her parents, Robert and Laura Edwards," the statement read.

Besides running the home, where she looked after 20 children, she also ran a food centre catering for 160 children a day and helped raised funds to subsidise their schooling. 

Estes Church said: "Roberta was a light to those in the community and dedicated to bringing hope to the hopeless. She knew that she worked in a dangerous setting, but had committed herself to care for children in Haiti despite these risks. Roberta has received her reward for her dedication to serving the Lord in Haiti. She will be missed in Haiti by her children, the community and friends. She will be missed here in the States as an encouragement and inspiration to us all. It is our intention to honor her memory by continuing the battle against Satan in Haiti and pressing on in the work of God's kingdom."

The Christian Chronicle profiled her work in response to the 2010 earthquake in Port-au-Prince, in which one child from the home was killed, in which the magazine described how she built her ministry from the collapse of her marriage. She had moved from the United States to Haiti in 1995 with her Haitian husband and was already caring for several children when the relationship broke down a few years later.