A Chinese city has reported the killings of three villagers in an area where North Korean border guards have been accused of crossing over to commit thefts and murders.

The Helong city government said a 55-year-old man surnamed Zhao, his 26-year-old daughter and another man aged 67 were killed on Saturday. It said in a statement Thursday that police from the provincial level down were investigating.

The killings took place in Longcheng township along the North Korean border, not far from where at least seven villagers were reported killed last year by border guards who had crossed the Tumen River that separates the countries in search of money and food.

China and North Korea are traditional allies, but the North's desperate economic situation is testing the relationship.