Thirteen Turks accused of assaulting two US sailors in Istanbul are facing a decade in prison after being charged with causing insult and injury and violating protest laws, according to an indictment.

Members of the Turkish Youth Union (TGB), a self-defined neo-nationalist anti-imperialist group, attacked the sailors on a crowded street on November 12, roughing them up, shouting "Yankee go home", throwing paint at them and briefly putting sacks over their heads.

Video footage was later posted on TGB's website.

The prosecutors' indictment, published by Turkey’s Dogan news agency on Thursday, quoted testimony from the two sailors in which they described being followed from the US navy destroyer USS Ross, which was docked in Istanbul, as they took shore leave.

The attackers say their action was inspired by an incident in Iraq in July 2003, when US forces detained a Turkish special forces unit, leading them away for interrogation with sacks over their heads. The incident enraged many Turks at the time.

Mevlut Cavusoglu, Turkish foreign minister, had described the assault as reprehensible and pledged that the attackers would "pay the price."

According to the indictment cited by Dogan, prosecutors are seeking jail sentences of 10 and a half years for the attackers.

The TGB defended its members' actions on Thursday, pledging at a news conference not to abandon their struggle "even if they were jailed for a hundred years".

The group told Al Jazeera after the incident that the action was a response to what TGB called American imperialism, US influence on Turkey's domestic affairs and the 2003 incident in Iraq.

Turkey, a NATO member, is a key US ally in the Middle East, but there is anti-American sentiment in some parts of society.

This is the third such incident reported in Turkey.

An American soldier was reportedly assaulted and a sack was put over his head in the Aegean holiday city of Mugla in 2012.

In a separate incident, two German NATO troops were subjected to the same treatment in the southern city of Hatay in 2013.

Source: Al Jazeera and agencies