Relatives of Pakistani students arrested in Britain over an alleged Al-Qaeda-driven plot pleaded their innocence and demanded access to their loved ones. Twelve men, including 11 Pakistanis -- 10 of them on student visas -- and a Briton, were arrested in raids across United Kingdom last Wednesday. One man has been released without charge. A five-day extension of their custody ends Wednesday. "I am celebrating the 23rd birthday of my son today with a heavy heart, not knowing what might have happened to him," Nasrullah Khattak, a property dealer based in Pakistan's northeastern city of Peshawar, told a foreign news agency by telephone. He said his son was a third-year student of information technology in Manchester and was guilty only of practising Islam. "I am really at a loss to understand what was his crime. Is he being punished for being a practising Muslim?" Families said neither the British nor the Pakistani government had provided any information, charging that news of their fate was leaked in the media. "I am clueless about my son because neither the British government nor the Pakistani foreign office or interior ministry approached me so far. I need to see my son, I want to know how is he doing and if he is alright," said Khattak.