An Afghan immigrant in the US has pleaded "not guilty" to plotting an attack in New York City. Najibullah Zazi has now been ordered to be held without bail during his hearing.

He made his first appearance in court on Tuesday after being arrested last week in connection with an alleged plot to attack New York City's transit system.

Federal investigators are scouring his old neighbourhood - something that has put the local Muslim community there on edge. Al Jazeera's Kristen Saloomey reports.