A young Muslim woman is suing police after she was mistakenly identified as a potential “lone wolf” terrorist during Fourth of July celebrations because she was wearing a headscarf and veil and carrying a backpack.

Itemid al-Matar said officers from the Chicago police force violated her civil rights by pulling off her religious garb as they arrested her on subway station stairs, then strip-searched her at a police station.

“Several [officers] ran up the stairs and grabbed the plaintiff and threw her down upon the stair landing, then pulling at her and ripping off her hijab,” says a federal lawsuit filed on Thursday.

Itemid al-Matar was apprehended on the subway during Fourth of July celebrations (YouTube)

CCTV footage from the incident last year that has been made public showed several minutes of the arrest in the subway. Several officers could be seen pushing through a crowd on a stairway to reach Ms Matar, but soon move out of view of the camera.

The fact that Ms Matar was wearing a hijab and niqab “was the impetus behind the actions” of the officers, the court filing alleges. In a statement issue can d on Thursday, Phil Robertson, a lawyer for the Chicago chapter of the Council on American-Islamic Relations (CAIR), and a lawyer involved in the case said “blatant xenophobia, Islamophobia, and racial profiling” underpinned the officers' actions.

A police report filed on the night of the incident says officers had been “on high alert of terrorist activity” on the Fourth of July holiday when they spotted Ms Matar exhibiting what they believed was suspicious behaviour, including walking at “a brisk pace, in a determined manner”. It also says officers saw what they thought could be incendiary devices around her ankles and were also suspicious of her backpack, which was clutched to her chest.

“[Officers] believed that subject might be a lone wolf suicide bomber and decided to attempt to take subject into custody,” it says.

A K-9 unit searched for explosive materials, the report says, “with negative results” while the objects strapped around her ankles’ turned out to be ankle weights.

But MS Matar was still charged, including with obstructing justice after police accused her of resisting and refusing to comply with orders. She was acquitted on all charges at a state trial earlier this year.

Thursday's lawsuit named six officers and the city of Chicago as defendants, accusing them of excessive force, false arrest, violation of freedom of religious expression and malicious prosecution.

A police spokesman declined to comment specifically on the suit, saying the department did not comment on pending litigation. But police issued a brief written statement that said: “Officers work hard each day to investigate suspicious activity and fight crime and we strive to treat all individuals with the highest levels of dignity of respect.”