WASHINGTON (AFP) - An American has been charged with attacking a US base abroad and providing information about New Yorks subway to Al-Qaeda, according to court documents unsealed Wednesday. Bryant Neal Vinas, described by US media as a 26-year-old man born in the US, pleaded not guilty to conspiracy to commit murder and providing support to a foreign terror group. st organisation, charges brought against him after his arrest last November. According to court documents filed with the office of US attorney Benton Campbell, the US government said that in or about Sept 2008, the defendant fired rockets at a US military base in Afghanistan. and that between March and November 2008, Vinas and other unnamed people did knowingly, intentionally and with malice aforethought conspire to kill one or more nationals of the United States. With regard to the New York charges, the court documents said Vinas provided material support and resources... including expert advice and assistance, including assistance derived from specialised knowledge of the New York transit system and Long Island Railroad. Vinas - also known as Ibrahim or Bashir al-Ameriki, according to the documents - has been detained without bail since his arrest, with a judge in the US district court in the eastern district of New York deeming him a flight risk and a danger to the community. According to the documents, Vinas travelled abroad and received a military-type training from and on behalf of a foreign terrorist organisation, to wit: Al-Qaeda. The New York Times reported Wednesday that Vinas was Long Island man who converted to Islam at a mosque there and was arrested in Pakistan where he had received the Al-Qaeda training. The daily, citing anonymous officials, reported that after his arrest Vinas began to cooperate with US and European counterterrorism officials, and that he was a key witness in a pair of terror prosecutions in Europe. The court documents do not refer to a specific terror plot against targets in New York. But last November, the Federal Bureau of Investigation warned US officials of a possible Al-Qaeda plot against New Yorks subway and transport grid, putting the citys police on heightened alert on the national Thanksgiving holiday. At the time the FBI said the threat was unsubstantiated, but acknowledged it received uncorroborated but plausible information that Al-Qaeda may have discussed a target at the transit system in New York City, according to a spokeswoman for the Department of Homeland Security.