“We have since last week detained more than 500 Afghans staying illegally in Balochistan and they are being deported,” Shoaib Suddle, police chief of the province told AFP.
The first 150 were scheduled to be deported later on Thursday at the border town of Chaman.
“It is for the Afghan authorities to find out who is a Taliban among them but we suspect there may be many such elements in the lot,” Mr Suddle said.
The mass arrests mark the first large-scale effort by Pakistan to expel illegal Afghans from Balochistan and follows months of accusations that Taliban commanders and fighters are living freely in the province and orchestrating a guerilla campaign inside Afghanistan from Pakistani soil.
Balochistan shares a porous and ill-defined 1,250 kilometre frontier with Afghanistan and is home to around one million of the 1.7 million Afghan refugees still in Pakistan, in addition to unknown numbers of illegal Afghan immigrants.
President Pervez Musharraf gave the order to expel illegal Afghan immigrants from Balochistan, a senior interior ministry official said.
Officials say it is difficult to distinguish between illegal immigrants and officially recognised refugees, but Mr Suddle stressed that only those Afghans who lacked valid documents were targeted.
The detainees have all been fingerprinted and photographed, he said.
The police on Thursday sent 123 Afghan nationals to Afghanistan from District Jail Quetta. They had been arrested from the city during the last one-week operation under foreigners act, official sources said.
They were boarded on trucks and sent to Chaman for deportation to their native land by Frontier Corps.—Agencies