Former US President Donald Trump narrowly escaped an assassination attempt at a campaign rally on Saturday. The 78-year-old Republican had just started his speech during at the event in Butler, Pennsylvania when the shots rang out and one of the bullets grazed his ear.

A video is now going viral that shows a woman sitting right behind Donald Trump acting strange -  moments after the shooting.

The video shows the woman - wearing sunglasses, a white shirt and a black hat - ducking and pulling out her phone as the shots rang out.

One user also pointed out that she was looking in the direction of the snipers.

The viral video has added fuel to several conspiracy theories doing rounds on social media following the shooting incident.

Several people on social media called her behaviour "highly suspicious, while others opined it could be a "harmless coincidence".

A moment of terrifying political violence at the rally instantly turned into a piece of Donald Trump iconography that's likely to turbocharge his presidential bid.

Images of a defiant Trump - with his fist raised over his head and his bloody right ear, as Secret Service agents surround him and the American flag waving in the background - are blazing across social media and television.

Applause and cheering spread through the grounds as Trump, clearly dazed, pumped his fist and waved through the linked arms of his security detail at the stunned crowd.