Security forces sealed a seminary in Quetta on Sunday and took at least 100 Afghan students into custody for studying in the institution without any valid documents.
According to a security official, the Afghan students were later handed over to various police stations for further questioning.
Giving details of the raid, the official said that a search operation was conducted inside the seminary and the Afghan students were arrested under the foreigners act.
He said that the Afghan nationals who were illegally staying at the seminary would be repatriated to Afghanistan.
In the aftermath of the Quetta carnage which left over 70 people, most of them lawyers, dead, security forces had intensified the operation.
The paramilitary Frontier Corps and police arrested a large number of Afghan refugees residing in Pakistan without any valid documents.
Action has been taken after the security forces apprehended six militants including a key commander of Al Qaeda in Balochistan’s Noshki district close to the Afghan border on Saturday.