Maulana Mohammad Khan Shirani was on way to his hometown in Qila Saifullah district, some 220km, east of here when his vehicle hit a landmine planted near the roadside, a security official said.
The vehicle was damaged but Shirani and the others with him, including his bodyguard, escaped unhurt.
The blast was believed to have been triggered by a remote control device, the official said, requesting anonymity.
He said two suspects with a remote control were captured later in nearby hills.
Shirani is provincial chief of the MMA and a member of the Parliament.
MMA shares power in the Balochistan government, which is led by the PML.