Washington, May 1 (IANS) Two US citizens have been indicted for providing Al Qaeda with computer expertise and other technical support to help modernise the terrorist outfit.

Prosecutors identified the men as Wesam El-Hanafi, 33, an American citizen, and Sabirhan Hasanoff, 34, a dual citizen of the US and Australia.

According to an indictment unsealed Friday in Federal District Court in Manhattan, both the men, former residents of Brooklyn, have been charged with conspiring to provide Al Qaeda with computer advice and other assistance.

They "conspired to modernise Al Qaeda by providing computer systems expertise" and other services, said Preet Bharara, US attorney for the Southern District of New York.

His office said the investigation was continuing. According to spokeswoman, Yusill Scribner, there were "no allegations of an active plot".

The indictment charged that the two men had assisted Al Qaeda since at least November 2007, The New York Times reported.

El-Hanafi went to Yemen in 2008, "where he met with two members of Al Qaeda who instructed him on operational security measures and directed him to perform tasks" for the group. In Yemen, he also swore an oath of allegiance to Al Qaeda, the indictment said.

El-Hanafi later bought a subscription to a software program that "enabled him to communicate securely with others over the internet," prosecutors charged.

Each man was charged with one count of conspiracy to provide material support to a foreign terrorist organisation. Each could face 15 years in prison if convicted, prosecutors said.

The indictment also cited an unidentified co-conspirator, listed only as CC-1.

In late 2007, CC-1 paid $50,000 to Hasanoff, and later had a discussion with both men "about joining Al Qaeda", the indictment said, adding that El-Hanafi also directed CC-1 to perform tasks for the terrorist group.

In April 2009, El-Hanafi bought seven Casio digital watches over the internet, and had them shipped to his home in Brooklyn, the indictment said.

Police Commissioner Raymond W. Kelly said, "This case's nexus to New York City serves as another reminder that we remain vigilant to the possibility of supporters of Al Qaeda returning to New York."

Both men were ordered detained by a federal magistrate judge in Alexandria, Va., and will be brought to Manhattan for further proceedings, prosecutors said.

El-Hanafi's lawyer, Victor Knapp, said his client had been in Dubai with his family, but when they tried to return to the US a few months ago, El-Hanafi was blocked and told that he was on a no-fly list. Knapp said his client was trying to return voluntarily, and then was arrested there a few days ago.

Hasanoff's lawyer, Anthony L. Ricco, said his client had also been arrested in Dubai and brought back to face charges.

Ricco said he was optimistic that once Hasanoff was in New York, he would be able to obtain his release on bail.

"I don't think there are any allegations he's a continuing threat to the community," Ricco said.