A Pakistani government official says Iranian security forces have killed six Pakistani traders taking goats into Iran, Today's Zaman reported.
Abdur Rehman said the incident happened Thursday on the Iranian side of the border near the Pakistani town of Gwadar.
Iranian authorities were not immediately available for comment.
Rehman said Iranian authorities were not releasing the bodies.
Earlier this month, Iranian security personnel allegedly crossed into southwest Pakistan and killed one man.
There is occasional violence along the poorly marked border, where smuggling, banditry and terrorism are rife.