Lithuanian cybersecurity experts are urging the country’s government agencies to stop using Chinese smartphone brands after an investigation revealed security flaws and censorship concerns with specific devices.

The National Cyber Security Center of Lithuania said it discovered four major cybersecurity risks for Huawei and Xiaomi devices, including two involving pre-installed apps and one involving personal data leakage, and warned against using these two brands.

Xiaomi phones, which include a content-filtering feature for 449 keywords or groups of keywords in Chinese characters, may also pose a risk of limiting freedom of expression, according to the Lithuanian investigation.

The cybersecurity center warned that the feature could be activated at any time and that it did not rule out the possibility of adding words written in Latin characters. Apps receive updated lists of censored words and phrases and can block them, according to the Lithuanian report.

“Free Tibet,” “Voice of America,” “Democratic Movement,” and “Long Live Taiwan Independence” are among the phrases. Although the content-filtering feature was deactivated and no censorship was carried out on the phones examined by the Lithuanian center, the center warned that the function could be activated at any time.

In Lithuania, a Huawei spokesperson denied the allegations. Xiaomi denied that its phones could be used to censor or pose privacy risks, claiming that they met the strict privacy regulations of the European Union.

According to the company, “Xiaomi’s devices do not censor communications to or from its users.” “Xiaomi has never and will never restrict or block any of our smartphone users’ personal behaviors, such as searching, calling, web browsing, or using third-party communication software. Xiaomi fully respects and protects all users’ legal rights.”

The cybersecurity center, which is part of the Defense Ministry, also looked into phones made by another Chinese company, OnePlus, but found no issues. “We strongly advise state and public institutions not to use those devices, and we intend to introduce legislation that regulates the acquisition of certain devices for ministries and various state agencies,” said Deputy Defense Minister Margiris Abukevicius on Wednesday.

More than 200 government agencies have purchased such phones, and over 4,500 are in use, “which, in our opinion, raises the risks,” Abukevicius said. He didn’t say what brand each phone was.

The investigation, which was made public on Tuesday, was conducted “to ensure the safe use of 5G mobile devices sold in our country and the software they contain,” he said.

Furthermore, “ordinary people should also know what’s inside these phones, about the specific software, and consider safety before making their decisions,” according to the minister.

Xiaomi, known for its low-cost devices, surpassed Samsung to become the world’s second-largest smartphone manufacturer by sales this year. The company was placed on a U.S. Defense Department blacklist in the final days of the Trump administration, after it was accused of having ties to China’s military. It was later removed after suing the US government, and it denies any ties to China’s People’s Liberation Army.

The move coincides with rising tensions between Lithuania and China. Lithuania recalled its ambassador to China earlier this month, following the Baltic country’s decision in July to allow Taiwan to open an office in its capital under its own name. China recalled its ambassador to Lithuania in August, telling the Baltic country to “immediately rectify its wrong decision.”

China claims Taiwan is part of its territory and does not have the right to diplomatic recognition, despite the fact that the island maintains informal ties with all major nations via trade offices, including those in the United States and Japan. Under Chinese pressure, Taiwan’s formal diplomatic allies have shrunk to just 15.

Taiwan and Lithuania agreed in July that the office in Vilnius, which is set to open this fall, will be called Taiwan rather than Chinese Taipei, a term commonly used in other countries to avoid offending Beijing. Lithuania announced on Wednesday that it was sending another 236,000 COVID-19 vaccines to Taiwan.