The soldiers of paramilitary Frontier Corps (FC) were moving during a routine patrolling when they were attacked in Sansar area of Gawadar.
In the attack, three FC soldiers were killed and four others injured, officials said.
"The security forces have cordoned off the area and launched search operation to apprehend the militants," a security official said.
Additional troops have been deployed in the area after the attack.
No group has claimed responsibility for the attack so far, but the nationalists Baloch rebels often target the security forces in the province, claiming that the government is depriving the region of its mineral resources.