Shenzhen Customs seized 18 million yuan ($2.6 million) in goods that infringed on intellectual property rights of Chinese enterprises last year, up 90 percent on 2015.

More than 260,000 items were confiscated, up by 33 percent year-on-year. Most were clothes, shoes and bags, although patent infringements on electronic products has been rising, the authority said.

Among the most common items found last year were smart balance wheels, also known as hoverboards.

According to customs officials in Dapeng, a district of Shenzhen, 9,300 units worth 9.85 million yuan were seized between mid-November and the end of December alone. The products were bound for the United States, Spain, Belgium, the Netherlands and Canada.

"We have made greater efforts to protect IPR and promote the development of innovative enterprises in science and technology," said Shen Hongyu, deputy director of regulation for Shenzhen Customs. "We have also participated in operations (with counterparts in Hong Kong and the US) to actively maintain the international image of 'made in China'."

An official with Dapeng's customs office who declined to be named said: "Awareness of IPR protection among businesspeople has been growing, and more enterprises are coming to us to ask for protection for inventions."

Shenzhen is home to many innovative enterprises, including Huawei and ZTE. The city's customs authority said a liaison mechanism has been set up for companies with a large number of patents to offer training and legal services.