Both sides ignored each other's proposals, and the KRA continued sending soldiers across the border to attack Vietnamese towns and villages. In September 1977, KRA artillery struck several Vietnamese villages along the border, and six villages in Đồng Tháp Province were overrun by Kampuchean infantry. Shortly afterwards, six divisions of the KRA advanced about into Tay Ninh Province, where they killed more than 1,000 Vietnamese civilians. Angered by the scale of Kampuchean assaults, the PAVN assembled eight divisions, estimated at around 60,000 soldiers, to launch a retaliatory strike against Kampuchea. On 16 December 1977, the PAVN divisions, with support from elements of the Vietnam People's Air Force, crossed the border along several axes with the objective of forcing the Kampuchean Government to negotiate.