New Delhi, Aug 12 - The US will ask Pakistan to bring all perpetrators of the 26/11 terror attack, including Hafiz Saeed, to justice, US Ambassador Timothy J. Roemer said here Wednesday, adding that Federal Bureau of Investigation (FBI) officials will testify in the trial of the Mumbai accused Mohammed Ajmal Amir alias Kasab this week.

'FBI officials are testifying in Mumbai this week,' the US envoy to India told reporters. 'The US stands firmly with India against terrorism.'

'All people held in Pakistan in connection with the Mumbai attacks should be brought to justice,' Roemer said when asked about the US stand on Pakistan's attitude towards Hafiz Saeed, the alleged mastermind of the Mumbai carnage.

The Supreme Court of Pakistan Aug 3 let off the Jammat-ud-Dawa (JuD) chief and the main accused in the 26/11 Mumbai terror attacks citing lack of evidence.

The court adjourned the hearing of Hafiz Saeed indefinitely based on the admission from the Pakistani government officials, including Interior Minister Rehman Malik, that their government had no concrete evidence to prosecute the JuD chief.