BEIJING - The Chinese manufacturer of Internet-censoring software that will become mandatory for all new computers next week has received death threats and been attacked by hackers, state media said Wednesday.

Workers at Jinhui Computer System Engineering Co. received more than 1,000 harassing phone calls, including death threats, this month, according to Zhang Chenmin, the general manager of the company.

"Most of the calls came late at night, cursing our staff and uttering obscenities, voicing their resentment against the software," Zhang was quoted as saying by the official Xinhua News Agency.

Phones rang unanswered Wednesday at company headquarters in the central Chinese city of Zhengzhou.

The Chinese government has come under pressure to scrap its plan to require the Internet-filtering Green Dam Youth Escort software on personal computers. The software, designed to block access to online pornography, is to be pre-installed or included on a compact disc with all PCs sold in China starting July 1.

Many Chinese Internet users have mocked the software, which is already available as a free download. The U.S. Embassy said Monday that Washington urged Beijing to reconsider its plan, saying it would restrict "the internationally recognized right to freedom of expression."

Zhang said personal information of some of the programmers had been leaked online, and that he had received a call threatening to kill his wife and child.

"I never expected the software to have brought us so many troubles. Our aim is simply to protect children from Internet pornography," he was quoted as saying.

The software has drawn criticism because it also blocks sites with discussions of homosexuality, mentions of the banned Falun Gong spiritual group and even images of pigs because the software confuses them with naked human bodies.

A California company, Solid Oak Software of Santa Barbara, also alleges that parts of a filtering software it designed appear in the Chinese software, raising questions about intellectual property violations.

China, which has the world's largest population of Internet users at more than 298 million, also has among the tightest controls on the Internet in the world, including on political content deemed challenging to the ruling Communist Party.