Pro-Russian troops in the Ukrainian town of Sloviansk posed with children, April 16, 2014. (ABC News)

Children in the eastern Ukrainian town of Sloviansk were all smiles today posing with pro-Russian soldiers who have taken the town.

The festive mood was thanks to the victory scored by the pro-Russian forces during Ukraine's "anti-terrorism operation," in which Ukrainian forces were trying to take back areas seized by the pro-Russian forces in the eastern part of the country.

Pro-Russian troops in the Ukrainian town of Sloviansk posed with children, April 16, 2014. (ABC News)

But many of the Ukrainian troops who arrived on a half dozen tanks and armored personnel carriers defected to the pro-Russian side during the operation, leaving the town in control of the pro-Russian forces and creating a celebratory atmosphere among residents who welcomed them.

A steady stream of children were sent up by their parents to pose with the towering men. Even adult couples and parents were snapped mugging with the soldiers.