WASHINGTON - US Justice Department has filed sealed criminal charges against one or several Libyan militants in connection with the deaths of four Americans in an attack on the US diplomatic post in Benghazi, Libya, US media reported Tuesday.

US prosecutors brought charges in a federal court in Manhattan against Ahmed Abu Khattalah, leader of a militant organization in Benghazi, CNN repoted. The charges are the first criminal counts to emerge from the probe into the Benghazi attack.

The Wall Street Journal reported later Tuesday that "a number" of suspects were charged for their alleged involvement in the September 11, 2012 assault, which killed US Ambassador to Libya Christopher Stevens and three other Americans.

Both reports cited anonymous sources, and they didn't say precisely what charges were brought against the defendents. The Justice Department has yet to confirm the reports.