Some of these 'Afghans' are people who have been born and brought up in Pakistan, never been to Afghaniland, and who see their future lives in Pakistan. Many have familial, marital, and social ties with Pakistanis in NWFP, Baluchistan, and even Punjab and Sindh.
A lot of jobs which many Pakistanis are loath to do, are carried out by Afghans, and they are contributing to society, making a living for themslves and their families.
Such Afghans, instead of being repatriated, should in fact be given Pakistani citizenship, so that the stresses and strains of being an illegal migrant be lifted from them.
The Afghans born in Pakistan, or with chidren born in Pakistan, must be given citizenship, as in any event, they are not going to back to a country that may now seem strange and alien to them.
On the other hand, Ttose Afghans who do not have such familial, social ties, new comers, especially those involved in illicit activities like prostitution, esp. in places like Islamabad, should be dealth with harshly, imprisoned and deported.