The telltale sign was in the writing on the shipping tape that bound the boxes. “Diplomatic bag” and “Stop: Do not open or detain,” read the tape in bold, capital letters, between DHL logos. The boxes, labeled in Chinese, contained pro-China T-shirts and flags, according to human rights group Amnesty International UK, and were distributed to crowds in time for Chinese President Xi Jinping’s procession down the Mall in London Tuesday as part of a four-day state visit to Britain.

As human rights advocates sought to make their voices heard and their banners seen during the procession, so did pro-China demonstrators wearing “I Heart China” T-shirts and carrying red banners with Chinese characters. The boxes, up to a dozen of which were scattered along with other detritus behind the monument of King George VI in London Tuesday morning, however, raised the question of who was behind the display of pro-China sentiment.

“There were thousands and thousands of pro-Chinese demonstrators,” Harriet Garland, a spokeswoman for Amnesty International UK, who was at the scene and took photos of the boxes, said in a telephone interview from London. Although the rights group was not able to confirm anything, “it did look very likely that these were diplomatic boxes filled with pro-China merchandise,” Garland said. Shipping labels and other markings on the box, such as the tape, seem to corroborate that hunch.

IMG_1463 Boxes containing pro-China merchandise were shipped as diplomatic cargo from Beijing to London ahead of Chinese President Xi Jinping's state visit to Britain, Oct. 20, 2015. Photo: Harriet Garland/Amnesty International UK

The King George VI monument represented just one entrance to the Mall, so the dozen boxes that Garland had seen could have been a fraction of the total number shipped, she said. She described the flags and banners as being of high quality, and said people were being encouraged to take the shirts.

The shipping label on one of the boxes was dated Oct. 13, 2015, according to a photo provided by Garland. It had been sent from “Logistics Supples [sic] of CN F A M”, in Dongcheng, a district of Beijing, and was addressed to “Embassy of P.R.C.,” the acronym for People’s Republic of China, in London.

FullSizeRender A shipping label on diplomatic boxes containing pro-China merchandise, like T-shirts and flags, is shown in London during Chinese President Xi Jinping's state visit to the U.K., Oct. 20, 2015. Photo: Courtesy of Harriet Garland/Amnesty International UK

Media on the ground reported that during Xi’s procession, pro-China supporters and demonstrators far outnumbered and drowned out those protesting China’s abysmal human rights record, including the groups Free Tibet and Amnesty International. Reuters reported that protesters and human rights campaigners were kept away from Xi’s procession, their signs overshadowed by flags that said, “I love China.”

“We were much fewer in number, and we were corralled in a pen,” Garland said, adding that pro-China demonstrators even went so far as to try to sabotage press coverage of the human rights campaigners. “Every time a journalist tried to take a [photo], they would obscure the shot,” she said.

Meanwhile, in China, state media covered the visit in an unusually positive light, predicting a "new type of political relationship" and extolling a new "golden era" in U.K.-China relations, the Financial Times reported Monday.