By Syed Shoaib Hasan
BBC News, Islamabad
The men were arrested on suspicion of trying to contact militant groups
Five US citizens held in Pakistan on suspicion of plotting attacks have alleged that US officials directed their torture to extract confessions.
The US embassy in Islamabad has dismissed the claims as "baseless".
The men, who are being held in the city of Sargodha, earlier stated in court that they had been tortured by the Pakistani authorities.
They deny claims they were plotting attacks in Pakistan and Afghanistan and had sought links with extremists.
The men, aged between 18 and 25, were arrested in Sargodha in November on suspicion of trying to contact al-Qaeda linked groups and plotting attacks against Pakistan and its allies.
Officials say the men were planning to travel to Afghanistan to fight with the Taliban. The men have denied having links to al-Qaeda and insist that they wanted to go to Afghanistan for charity work.
They face life imprisonment if put on trial and found guilty. A Pakistani court has barred their deportation to the US.
"The boys told me that Federal Bureau of Investigation (FBI) agents were present and were directing their interrogations," Khalid Khawaja, a human rights activist handling the case told the BBC.
"I have a written statement which says the Americans were asking them to which militant organisation they belonged.
"Pakistanis were beating them up and Americans kept asking them questions.
"The agents demanded they confess that they had come here (to Sargodha) to attack the nearby nuclear plant."
Mr Khawaja said that the men had also made accusations of torture in the court where their case is being heard.
He said it was only because of US pressure that the men had been arrested.
"There is no real evidence against them," he said.
"I intend to file a petition in the next few days asking the court to dismiss all charges against them."