A Pakistani madrassa slapped with US sanctions as an alleged terror training centre has denied the charges, insisting it teaches only religion and Arabic grammar to around 150 boys. The US Treasury said the Ganj seminary in the northwestern city of Peshawar was being used as a training and recruiting base by Al-Qaeda, the Taliban and militant group Lashkar-e-Taiba (LeT). The head of the madrassa, Fazeel-A-Tul Shaykh Abu Mohammed Ameen Al-Peshawari, known as Shaykh Aminullah, has been on UN and US terror blacklists since 2009. Shaykh Aminullah has not been seen at the school for eight months, the school\'s caretaker Haji Alam Sher told AFP. Sher denied any links to terrorist groups, saying that the seminary teaches 150-180 students. \"We teach different subjects including Islamic shariah, history and Arabic grammar to our students,\" he said. The pupils are currently on their summer holiday, Sher said. But Pakistani security officials confirmed to AFP that the school had been raided in the past and had close ties to LeT, the group blamed for killing 166 people in Mumbai in November 2011. \"There were no terrorist activities going on at the madrassa but we found out it was a Lashkar-e-Taiba nerve centre,\" a senior police official told AFP. He said a young man arrested on his way to fight in Afghanistan in 2011 was found to be carrying a \"certificate for heaven\" which had been given to him by the Ganj madrassa -- a piece of paper given to militants promising them paradise after their death. \"The madrassa used to issue similar certificates to all LeT men, who went to Afghanistan for jihad,\" the police officer said. A Pakistani intelligence official also told AFP that the madrassa was a centre for LeT activities. Thousands of madrassas in Pakistan educate some of the poorest children in the country. But they are not tightly regulated and have served as recruitment grounds for militant groups. The Ganj is the first madrassa hit by US sanctions, which forbid Americans from having any business interaction with it, and freeze any of its assets that come under US jurisdiction.