WASHINGTON - The US International Trade Commission (USITC) on Friday initiated four Section 337 investigations involving two kinds of Chinese products. This is the second time in four days that the US government used trade remedy actions.

The first product at issue is protective cases that used for handheld portable electronic devices. The probe is based on a complaint filed by Speculative Product Design, LLC based in California on December 26, 2012, said the USITC in a statement. Shengda Huanqiu Shijie of Shenzhen and another three companies from China were identified as respondents in the investigation.

The accuser claimed Section 337 violations involving patents infringement, and requested an exclusion order and cease and desist orders, according to the federal bipartisan panel.

The other product is smart phone and associated touch keyboard software that permits a user to input information with increased speed and/or accuracy. Four communications companies based in Massachusetts complained China's Shanghai Hanxiang (Coo Tek) Information Technology Co. Ltd. and another US company in New York state infringed their patents. They also requested an exclusion order and cease and desist orders.

The institution of the investigation does not mean the USITC has made any decision on the merits of the case. Within 45 days the body will set a target date for completing the investigation.

Should the complaint be approved, the panel will issue remedial orders, such as a ban on importation of accused products. ?

Daniel Ikenson, director of Center for Trade Policy Studies at Cato Institute, told Xinhua that the USITC action was redundant, because the patent holders had the right to sue at a regular court. More importantly, he added, Section 337 violates the rules of the World Trade Organization, and it is merely a protectionist relic that needs to go.

In January this year, the United States launched one antidumping and three Section 337 investigations against Chinese products. ?The Chinese Ministry of Commerce has repeatedly urged Washington to abide by its commitment against protectionism and help maintain a free, open and just international trade environment.