Yahoo email accounts of some journalists and activists whose work relates to China were compromised in an attack discovered this week, according to rights groups and foreign correspondents, days after Google said it would move its Chinese-language search services out of China because of censorship concerns.

Several journalists in China and Taiwan found they were unable to access their accounts beginning March 25, among them Kathleen McLaughlin, a freelance journalist in Beijing. Her access was restored on Wednesday, she told Reuters.

The compromised accounts included those of the World Uyghur Congress, an exile group that China accuses of inciting separatism by ethnic Uighurs in the frontier region of Xinjiang.

I suspect a lot of information in my Yahoo account was downloaded, the group's spokesman, Dilxat Raxit, told Reuters on Wednesday. He said the email account, set up in Sweden, has been inaccessible for a month.

A lot of people I used to contact in Lanzhou, Xi'an and elsewhere have not been reachable by phone for the past few weeks, he said, adding that he had used the Yahoo email account to contact them in the past.

Andrew Jacobs of the New York Times in Beijing said on Wednesday that his Yahoo Plus account had been set, without his knowledge, to forward to another, unknown, account.

In late 2009 and early this year, several human rights activists and journalists whose work related to China had discovered that their Gmail accounts had been set, without their knowledge, to forward to unfamiliar addresses.

Google cited the Gmail attacks in January, when it announced a hacking attack on it and more than 20 other companies. It cited those attacks and censorship concerns in its decision to move its Chinese-language search services last week to Hong Kong.

A source at the time told Reuters that Yahoo knew it had been a target of attacks and discussed them with Google before Google went public.

It was not immediately clear whether those incidents were related to the latest security breaches sustained by users of Yahoo mail.

Yahoo did not comment on the nature of the attacks on its accounts, or whether they were coordinated or isolated incidents.

Yahoo! condemns all cyber attacks regardless of origin or purpose, spokeswoman Dana Lengkeek said in an email response to a Reuters query.

We are committed to protecting user security and privacy and we take appropriate action in the event of any kind of breach.

CHINA PARTNERS

Yahoo's direct involvement in China has been limited since 2005, when it transferred control of its online operations to the Alibaba Group, a Chinese Internet company in which Yahoo owns a 39 percent stake.

Yahoo maintains a research and development facility in Beijing, but the company does not have any role in the day-to-day operations of the Yahoo China website, or maintain email servers in China. Email accounts tied to China's .cn domain are managed by Alibaba, which has servers in mainland China, a Yahoo spokeswoman said.

Despite Yahoo's limited direct involvement in China, analysts consider the company's China assets to be among its most valuable.

Clayton Moran, an analyst with The Benchmark Company, said he saw limited risk to Yahoo's Chinese assets from censorship and privacy issues, with the bigger risk relating to investor enthusiasm for the Chinese Internet market in general.

If you see a pullback in the Chinese economy, the Chinese Internet, or if multiples contract because investors get less excited about the China opportunity, then Yahoo's valuation will have a significant impact, Moran said.

China's regulatory and political environments have been sources of consternation for Yahoo in the past.

Yahoo was criticized by the U.S. Congress when it released to Chinese authorities information relating to the email account of Shi Tao, a Chinese journalist who was arrested in 2004, before Alibaba took over Yahoo's China operations. Shi Tao was sentenced to 10 years in jail for revealing state secrets.

After Google's January announcement about cyber attacks originating in China, Yahoo said it was aligned with Google's position, a statement that its Chinese partner, Alibaba Group, called reckless

Google's announcement of the hacking attacks drew unprecedented outside attention to cyber-security and China's Internet controls, used to limit discussion of topics deemed sensitive or threatening to social stability.

China's control of the Internet and media has intensified under the current leadership and reflects a lack of understanding of the Chinese public, said Hao Xiaoming, a China media expert at Wee Kim Wee School of Communication and Information in Singapore.

China is going back rather than going forward in terms of information and control. That reflects the lack of confidence in the (current) Chinese leaders, Hao said.

China's Internet has become a controlled Internet, an internal Internet rather than linked internationally. It defeats the whole purpose.

(Additional reporting by Melanie Lee in Shanghai; Editing by Ron Popeski and Sugita Katyal)