US President Donald Trump survived an assassination attempt during a rally in Pennsylvania but the injured former President's defiant image with his fist up in the air attracted business owners in China who quickly captured the moment to produce and sell T-shirts with the picture on them.

The first batch went on sale on Taobao, a popular Chinese e-commerce platform, at 8.40pm – before most governments around the world had scrambled together a response, reported South China Morning Post.

By the time the news spread across the world and Chinese people were up for their breakfast, the T-shirts were already available for purchasing online.

“We put the T-shirts on Taobao as soon as we saw the news about the shooting, though we hadn’t even printed them, and within three hours we saw more than 2,000 orders from both China and the US,”  Li Jinwei, a 25-year-old Taobao seller, told the newspaper.

Li’s factory is based in the northern province of Hebei, and to create new products, she simply downloads an image and presses print, with the factory taking an average of one minute to finish a T-shirt, the newspaper reported.

Former US President Donald Trump received injuries on his right ear during a Saturday election campaign rally at Pennsylvania's Butler, in what is seen as an assassination bid that left the 78-year-old Republican presidential candidate's face streaked with blood with his alert security agents rushing him off the stage even as he pumped his fist in the air, mouthing the words "Fight! Fight! Fight!"

The shooter, along with one bystander who was there to attend the rally, died.

As gunshots were heard, Trump, who was just six minutes into his election speech, was seen clutching a hand to his right ear, where blood was visible across his cheek and mouth.

Two other spectators were injured, the Secret Service said in a statement. The incident was being investigated as an assassination attempt.

Secret Service agents were quick to respond and surrounded Trump while escorting him off the stage, as he raised a fist to the crowd in defiance.