They said dozens of heavily armed militants attacked a border security post at Ghakhi Pass along the border with Afghanistan, Xinhua news agency reported.
An official told the media that the militants fled to the Afghan side of the border after Pakistani forces returned fire.
The Islamic State terrorist group claimed responsibility for the attack.
IS spokesman Shahidullah Shahid told media persons over phone that the group's fighters had launched the attack at 9 a.m.
Cross-border attacks have been a routine in Pakistan's troubled border provinces -- however, a substantial decrease has been witnessed in recent months.