(CNN) -- China's information technology ministry called accusations of government involvement in cyber attacks alleged by Google "groundless" in an interview with state-run media on Sunday.

The search-engine giant has threatened to pull out of China, saying that Chinese hackers have targeted Google and up to 34 other companies.

"Accusation that the Chinese government participated in [any] cyber attack, either in an explicit or inexplicit way, is groundless and aims to denigrate China," the official Xinhua News Agency quoted a spokesman for the Ministry of Industry and Information Technology as saying. "We are firmly opposed to that."

In a speech on Internet freedom and security Thursday in Washington, U.S. Secretary of State Hillary Clinton urged China to investigate such attacks, saying they raised "very serious concerns."

In response, Ma Zhaoxu, a spokesman for China's Ministry of Foreign Affairs, said Friday: "We're firmly against this statement that goes against truth and damages U.S.-Sino relationship."

The ministry spokesman sought to reassert that stance Sunday, saying "China's policy on Internet safety is transparent and consistent," according to Xinhua.

He also noted China has launched Internet safety campaigns against such attacks, Xinhua reported.

Five years ago, Google agreed to allow some censorship by China, in exchange for the right to operate in that country's massive emerging technology market. The company now says censorship and the hacking of Chinese dissidents' Google e-mail accounts have prompted it to reconsider.

STORY HIGHLIGHTS

•     Google says Chinese hackers have targeted it and up to 34 other companies
•     Search-engine giant has threatened to pull out of China
•     China: Accusations of government involvement in alleged attacks "groundless"
•     Secretary of State Hillary Clinton urged China to investigate